TY  - JOUR
A1  - Bäcker, Matthias
A1  - Kowollik, Silvia
A1  - Schnitzler, Thomas
A1  - Wang, J.
A1  - Poghossian, Arshak
A1  - Zang, Werner
A1  - Biselli, Manfred
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Entwicklung eines festkörperbasierten Sensorsystems für die Bioprozessautomatisierung
JF  - 9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]
Y1  - 2009
SN  - 978-3-941298-44-6
N1  - Dresdner Sensor-Symposium ; (9, 2009, Dresden)
SP  - 197
EP  - 200
PB  - TUDpress
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
A1  - Yoshinobu, Tatsuo
A1  - Lüth, Hans
T1  - Semiconductor-based field-effect structures for chemical sensing
Y1  - 2001
SP  - 188
EP  - 198
ER  - 
TY  - CHAP
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Leinhos, Marcel
A1  - Krischer, M.
A1  - Wenzel, L.
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Sensorkonzept zur in vitro Echtzeitmessung des Degradationsverhaltens von biodegradierbaren Biopolymeren
T2  - 11. Dresdner Sensor-Symposium : 9.-11.12.2013
Y1  - 2013
SN  - 978-3-9813484-5-3
SP  - 174
EP  - 177
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Thust, M.
A1  - Schöning, Michael Josef
A1  - Müller-Veggian, Mattea
A1  - Kordos, P.
A1  - Lüth, H.
T1  - Cross-sensitivity of a capacitive penicillin sensor combined with a diffusion barrier
JF  - Sensors and Actuators B. 68 (2000), H. 1-3
Y1  - 2000
SN  - 0925-4005
SP  - 260
EP  - 265
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Brinkmann, D.
A1  - Demuth, C.
A1  - Poghossian, Arshak
T1  - CIP (cleaning-in-place)-suitable „non-glass“ pH sensor based on a Ta2O5-gate EIS structure
JF  - Digest of technical papers : September 12 - 15, 2004, Rome, Italy, Pontificia Universitas Sancto Thoma Aquinate in Urbe / [conference chairperson: C. Di Natale].
Y1  - 2004
SN  - 88-7621-282-5
N1  - Eurosensors ; (18, 2004, Roma)
SP  - 857
EP  - 860
CY  - Roma
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Berndsen, Lars
A1  - Lüth, Hans
A1  - Schöning, Michael Josef
T1  - Novel concepts for flow-rate and flow-direction determination by means of pH-sensitive ISFETs
JF  - Proceedings of SPIE. 4560 (2001)
Y1  - 2001
SP  - 19
EP  - 27
ER  - 
TY  - JOUR
A1  - Honarvarfard, Elham
A1  - Gamella, Maria
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
T1  - An enzyme-based reversible Controlled NOT (CNOT) logic gate operating on a semiconductor transducer
JF  - Applied Materials Today
N2  - An enzyme-based biocatalytic system mimicking operation of a logically reversible Controlled NOT (CNOT) gate has been interfaced with semiconductor electronic transducers. Electrolyte–insulator–semiconductor (EIS) structures have been used to transduce chemical changes produced by the enzyme system to an electronically readable capacitive output signal using field-effect features of the EIS device. Two enzymes, urease and esterase, were immobilized on the insulating interface of EIS structure producing local pH changes performing XOR logic operation controlled by various combinations of the input signals represented by urea and ethyl butyrate. Another EIS transducer was functionalized with esterase only, thus performing Identity (ID) logic operation for the ethyl butyrate input. Both semiconductor devices assembled in parallel operated as a logically reversible CNOT gate. The present system, despite its simplicity, demonstrated for the first time logically reversible function of the enzyme system transduced electronically with the semiconductor devices. The biomolecular realization of a CNOT gate interfaced with semiconductors is promising for integration into complex biomolecular networks and future biosensor/biomedical applications.
KW  - Electrolyte–insulator–semiconductor
KW  - Capacitive field-effect
KW  - CNOT
KW  - XOR
KW  - Enzyme logic gate
Y1  - 2017
U6  - https://doi.org/10.1016/j.apmt.2017.08.003
SN  - 2352-9407
VL  - 9
SP  - 266
EP  - 270
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Beging, Stefan
A1  - Rotter, L.
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Zang, Werner
A1  - Schöning, Michael Josef
T1  - Online-Messsysteme für die automatisierte Charakterisierung von feldeffektbasierten Biosensoren
JF  - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)
Y1  - 2007
SN  - 978-3-940046-45-1
N1  - Dresdner Sensor-Symposium <8, 2007, Dresden> ; Dresdner Beiträge zur Sensorik ; 29
SP  - 257
EP  - 260
PB  - TUDpress, Verl. der Wissenschaften
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Ecken, H.
A1  - Poghossian, Arshak
A1  - Simonis, A.
A1  - Iwasaki, H.
A1  - Lüth, H.
A1  - Schöning, Michael Josef
T1  - Constant-current-mode LAPS (CLAPS) for the detection of penicillin
JF  - Electroanalysis. 13 (2001), H. 8-9
Y1  - 2001
SN  - 1040-0397
SP  - 733
EP  - 736
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Abouzar, Maryam H.
A1  - Schöning, Michael Josef
T1  - Capacitance–voltage and impedance characteristics of field-effect EIS sensors functionalised with polyelectrolyte multilayers
JF  - IRBM. 29 (2008), H. 2-3
Y1  - 2008
SN  - 1959-0318
SP  - 149
EP  - 154
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Lüth, H.
A1  - Schultze, J. W.
A1  - Schöning, Michael Josef
T1  - (Bio-)chemical and physical microsensor array using an identical transducer principle
JF  - Scaling down in electrochemistry : electrochemical micro- and nanosystem technology ; proceedings of the 3rd International Symposium on Electrochemical Microsystem Technologies, Garmisch-Patenkirchen, Germany, 11 - 15 September 2000 / ed. by J. W. Schultz
Y1  - 2001
SN  - 0-08-044014-2
SP  - 243
EP  - 249
PB  - Elsevier [u.a.]
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
T1  - BioFEDs (field-effect devices) : State-of-the-art and new directions
JF  - Electroanalysis
Y1  - 2006
U6  - https://doi.org/10.1002/elan.200603609
SN  - 1521-4109
VL  - 18
IS  - 19-20
SP  - 1893
EP  - 1900
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Kerroumi, Iman
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Zander, Willi
A1  - Schubert, Jürgen
A1  - Buniatyan, Vahe V.
A1  - Martirosyan, Norayr W.
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Multiparameter sensor chip with Barium Strontium Titanate as multipurpose material
JF  - Electroanalysis
N2  - It is well known that biochemical and biotechnological processes are strongly dependent and affected by a variety of physico-chemical parameters such as pH value, temperature, pressure and electrolyte conductivity. Therefore, these quantities have to be monitored or controlled in order to guarantee a stable process operation, optimization and high yield. In this work, a sensor chip for the multiparameter detection of three physico-chemical parameters such as electrolyte conductivity, pH and temperature is realized using barium strontium titanate (BST) as multipurpose material. The chip integrates a capacitively coupled four-electrode electrolyte-conductivity sensor, a capacitive field-effect pH sensor and a thin-film Pt-temperature sensor. Due to the multifunctional properties of BST, it is utilized as final outermost coating layer of the processed sensor chip and serves as passivation and protection layer as well as pH-sensitive transducer material at the same time. The results of testing of the individual sensors of the developed multiparameter sensor chip are presented. In addition, a quasi-simultaneous multiparameter characterization of the sensor chip in buffer solutions with different pH value and electrolyte conductivity is performed. To study the sensor behavior and the suitability of BST as multifunctional material under harsh environmental conditions, the sensor chip was exemplarily tested in a biogas digestate.
Y1  - 2014
U6  - https://doi.org/10.1002/elan.201400076
SN  - 1521-4109 (E-Journal); 1040-0397 (Print)
VL  - 26
IS  - 5
SP  - 980
EP  - 987
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Rolka, David
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Integration of a capacitive EIS sensor into a FIA system for pH and penicillin determination
JF  - Sensors. 4 (2004)
Y1  - 2004
SN  - 1424-8220
SP  - 84
EP  - 94
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Detecting Both Physical and (Bio-)Chemical Parameters by Means of ISFET Devices
JF  - Electroanalysis. 16 (2004), H. 22
Y1  - 2004
SN  - 1040-0397
SP  - 1863
EP  - 1872
ER  - 
TY  - JOUR
A1  - Siqueira, José R. Jr.
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Zucolotto, Valtencir
A1  - Oliveira, Osvaldo N. Jr.
A1  - Schöning, Michael Josef
T1  - Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer/carbon nanotube multilayer
JF  - Biosensors and Bioelectronics. 25 (2009), H. 2
Y1  - 2009
SN  - 0956-5663
SP  - 497
EP  - 501
ER  - 
TY  - JOUR
A1  - Gamella, Maria
A1  - Zakharchenko, Andrey
A1  - Guz, Nataliia
A1  - Masi, Madeline
A1  - Minko, Sergiy
A1  - Kolpashchikov, Dmitry M.
A1  - Iken, Heiko
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
T1  - DNA computing system activated by electrochemically triggered DNA realease from a polymer-brush-modified electrode array
JF  - Electroanalysis
N2  - An array of four independently wired indium tin oxide (ITO) electrodes was used for electrochemically stimulated DNA release and activation of DNA-based Identity, AND and XOR logic gates. Single-stranded DNA molecules were loaded on the mixed poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA)/poly(methacrylic acid) (PMAA) brush covalently attached to the ITO electrodes. The DNA deposition was performed at pH 5.0 when the polymer brush is positively charged due to protonation of tertiary amino groups in PDMAEMA, thus resulting in electrostatic attraction of the negatively charged DNA. By applying electrolysis at −1.0 V(vs. Ag/AgCl reference) electrochemical oxygen reduction resulted in the consumption of hydrogen ions and local pH increase near the electrode surface. The process resulted in recharging the polymer brush to the negative state due to dissociation of carboxylic groups of PMAA, thus repulsing the negatively charged DNA and releasing it from the electrode surface. The DNA release was performed in various combinations from different electrodes in the array assembly. The released DNA operated as input signals for activation of the Boolean logic gates. The developed system represents a step forward in DNA computing, combining for the first time DNA chemical processes with electronic input signals.
Y1  - 2017
U6  - https://doi.org/10.1002/elan.201600389
SN  - 1521-4109
VL  - 29
IS  - 2
SP  - 398
EP  - 408
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Razavi, Arash
A1  - Besmehn, Astrid
A1  - Bijnens, Nathalie
A1  - Williams, Oliver A.
A1  - Haenen, Ken
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Penicillin detection with nanocrystalline-diamond field-effect sensor
JF  - physica status solidi (a). 205 (2008), H. 9
Y1  - 2008
SN  - 1862-6319
N1  - Special Issue: Hasselt Diamond Workshop 2008 - SBDD XIII
SP  - 2141
EP  - 2145
ER  - 
TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Ingebrandt, S.
A1  - Poghossian, Arshak
A1  - Zhang, Y.
A1  - Moritz, W.
A1  - Schöning, Michael Josef
T1  - Field-effect nanoplate capacitive pH sensor based on SOI structure
JF  - Semiconductor micro- and nanoelectronics : Proceedings of the Seventh International Conference , Tsakhcadzor, Armenia July 3-5 2009
Y1  - 2009
SP  - 55
EP  - 58
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - "High-order” hybrid FET module for (bio)chemical and physical sensing
JF  - Integrated analytical systems / ed. by Salvador Alegret
Y1  - 2003
SN  - 0-444-51037-0
SP  - 587
EP  - 623
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Wu, Chunsheng
A1  - Bronder, Thomas
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Schöning, Michael Josef
T1  - Label-free detection of DNA using light-addressable potentiometric sensor modified with a positively charged polyelectrolyte layer
JF  - Nanoscale
N2  - A multi-spot (16 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al–p-Si–SiO2 structure modified with a weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. To achieve a preferentially flat orientation of DNA strands and thus, to reduce the distance between the DNA charge and MLAPS surface, the negatively charged probe single-stranded DNAs (ssDNA) were electrostatically adsorbed onto the positively charged PAH layer using a simple layer-by-layer (LbL) technique. In this way, more DNA charge can be positioned within the Debye length, yielding a higher sensor signal. The surface potential changes in each spot induced due to the surface modification steps (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), non-specific adsorption of mismatched ssDNA) were determined from the shifts of photocurrent–voltage curves along the voltage axis. A high sensor signal of 83 mV was registered after immobilization of probe ssDNA onto the PAH layer. The hybridization signal increases from 5 mV to 32 mV with increasing the concentration of cDNA from 0.1 nM to 5 μM. In contrast, a small signal of 5 mV was recorded in the case of non-specific adsorption of fully mismatched ssDNA (5 μM). The obtained results demonstrate the potential of the MLAPS in combination with the simple and rapid LbL immobilization technique as a promising platform for the future development of multi-spot light-addressable label-free DNA chips with direct electrical readout.
Y1  - 2015
U6  - https://doi.org/10.1039/C4NR07225A
VL  - 14
IS  - 7
SP  - 6143
EP  - 6150
PB  - Royal Society of Chemistry (RSC)
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Buniatyan, V.
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Aroutiounian, V. M.
A1  - Schöning, Michael Josef
T1  - BaxSr1-x TiO3/pc-Si heterojunction
JF  - Armenian journal of physics
Y1  - 2013
SN  - 1829-1171
VL  - 6
IS  - 4
SP  - 177
EP  - 187
PB  - National Academy of Sciences of Armenia
CY  - Yerevan
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Ecken, H.
A1  - Poghossian, Arshak
A1  - Lüth, H.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - Alternative sensor materials for light-addressable potentiometric sensors
JF  - Sensors and Actuators B. 76 (2001), H. 1-3
Y1  - 2001
SN  - 0925-4005
SP  - 388
EP  - 392
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Abouzar, Maryam H.
A1  - Sakkari, M.
A1  - Kassab, T.
A1  - Han, Y.
A1  - Ingebrandt, S.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Field-effect sensors for monitoring the layer-by-layer adsorption of charged macromolecules
JF  - Sensors and Actuators B: Chemical. 118 (2006), H. 1-2
Y1  - 2006
SN  - 0925-4005
N1  - Eurosensors XIX - Eurosensors XIX - The 19th European Conference on Solid-State Transducers
SP  - 163
EP  - 170
ER  - 
TY  - JOUR
A1  - Krämer, Melina
A1  - Pita, Marcos
A1  - Zhou, Jian
A1  - Ornatska, Maryna
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
T1  - Coupling of Biocomputing Systems with Electronic Chips: Electronic Interface for Transduction of Biochemical Information
JF  - Journal of Physical Chemistry C: Nanomaterials and Interfaces. 113 (2009), H. 6
Y1  - 2009
SN  - 1932-7455
SP  - 2573
EP  - 2579
PB  - American Cemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Wu, Chunsheng
A1  - Bronder, Thomas
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Bäcker, Matthias
A1  - Schöning, Michael Josef
T1  - Label-free electrical detection of DNA with a multi-spot LAPS: First step towards light-addressable DNA chips
JF  - Physica status solidi A : Applications and materials science
N2  - A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al–p-Si–SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent–voltage (I–V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I–V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.
Y1  - 2014
U6  - https://doi.org/10.1002/pssa.201330442
SN  - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1423
EP  - 1428
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Näther, Niko
A1  - Poghossian, Arshak
A1  - Platen, J.
A1  - Yoshinobu, T.
A1  - Koudelka-Hep, M.
A1  - Schöning, Michael Josef
T1  - Multi-parameter sensing of both physical and (bio-)chemical quantities using the same transducer principle
T2  - Biochemical sensing utilisation of micro- and nanotechnologies : Warsaw, [23rd - 26th] November 2005 / ed. by M. Mascini ...
Y1  - 2006
SP  - 172
EP  - 181
CY  - Warsaw
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Jablonski, Melanie
A1  - Molinnus, Denise
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Field-Effect Sensors for Virus Detection: From Ebola to SARS-CoV-2 and Plant Viral Enhancers
JF  - Frontiers in Plant Science
N2  - Coronavirus disease 2019 (COVID-19) is a novel human infectious disease provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, no specific vaccines or drugs against COVID-19 are available. Therefore, early diagnosis and treatment are essential in order to slow the virus spread and to contain the disease outbreak. Hence, new diagnostic tests and devices for virus detection in clinical samples that are faster, more accurate and reliable, easier and cost-efficient than existing ones are needed. Due to the small sizes, fast response time, label-free operation without the need for expensive and time-consuming labeling steps, the possibility of real-time and multiplexed measurements, robustness and portability (point-of-care and on-site testing), biosensors based on semiconductor field-effect devices (FEDs) are one of the most attractive platforms for an electrical detection of charged biomolecules and bioparticles by their intrinsic charge. In this review, recent advances and key developments in the field of label-free detection of viruses (including plant viruses) with various types of FEDs are presented. In recent years, however, certain plant viruses have also attracted additional interest for biosensor layouts: Their repetitive protein subunits arranged at nanometric spacing can be employed for coupling functional molecules. If used as adapters on sensor chip surfaces, they allow an efficient immobilization of analyte-specific recognition and detector elements such as antibodies and enzymes at highest surface densities. The display on plant viral bionanoparticles may also lead to long-time stabilization of sensor molecules upon repeated uses and has the potential to increase sensor performance substantially, compared to conventional layouts. This has been demonstrated in different proof-of-concept biosensor devices. Therefore, richly available plant viral particles, non-pathogenic for animals or humans, might gain novel importance if applied in receptor layers of FEDs. These perspectives are explained and discussed with regard to future detection strategies for COVID-19 and related viral diseases.
Y1  - 2020
U6  - https://doi.org/10.3389/fpls.2020.598103
VL  - 11
IS  - Article 598103
SP  - 1
EP  - 14
PB  - Frontiers
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Leinhos, Marcel
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers
JF  - Physica Status Solidi (A)
N2  - Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution.
Y1  - 2013
U6  - https://doi.org/10.1002/pssa.201200941
SN  - 1521-396X ; 0031-8965
VL  - 210
IS  - 5
SP  - 905
EP  - 910
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - BOOK
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
T1  - Label-free biosensing: advanced materials, devices and applications
Y1  - 2018
SN  - 978-3-319-75219-8
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Janus, Kevin Alexander
A1  - Achtsnicht, Stefan
A1  - Drinic, Aleksander
A1  - Kopp, Alexander
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Transient magnesium-based thin-film temperature sensor on a flexible, bioabsorbable substrate for future medical applications
JF  - Applied Research
N2  - In this work, the bioabsorbable materials, namely fibroin, polylactide acid (PLA), magnesium and magnesium oxide are investigated for their application as transient, resistive temperature detectors (RTD). For this purpose, a thin-film magnesium-based meander-like electrode is deposited onto a flexible, bioabsorbable substrate (fibroin or PLA) and encapsulated (passivated) by additional magnesium oxide layers on top and below the magnesium-based electrode. The morphology of different layered RTDs is analyzed by scanning electron microscopy. The sensor performance and lifetime of the RTD is characterized both under ambient atmospheric conditions between 30°C and 43°C, and wet tissue-like conditions with a constant temperature regime of 37°C. The latter triggers the degradation process of the magnesium-based layers. The 3-layers RTDs on a PLA substrate could achieve a lifetime of 8.5 h. These sensors also show the best sensor performance under ambient atmospheric conditions with a mean sensitivity of 0.48 Ω/°C ± 0.01 Ω/°C.
KW  - Silk fibroin
KW  - Polylactide  acid
KW  - Bioabsorbable
KW  - Resistive  temperature detector
Y1  - 2023
U6  - https://doi.org/10.1002/appl.202300102
SN  - 2702-4288 (Print)
N1  - Corresponding author: Michael Josef Schöning
IS  - Accepted manuscript
PB  - Wiley-VCH
ER  - 
TY  - JOUR
A1  - Janus, Kevin Alexander
A1  - Achtsnicht, Stefan
A1  - Tempel, Laura
A1  - Drinic, Aleksaner
A1  - Kopp, Alexander
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Influence of fibroin membrane composition and curing parameters on the performance of a biodegradable enzymatic biosensor manufactured from Silicon-Free Carbon
JF  - Physica status solidi : pss. A, Applications and materials science
N2  - Herein, fibroin, polylactide (PLA), and carbon are investigated for their suitability as biocompatible and biodegradable materials for amperometric biosensors. For this purpose, screen-printed carbon electrodes on the biodegradable substrates fibroin and PLA are modified with a glucose oxidase membrane and then encapsulated with the biocompatible material Ecoflex. The influence of different curing parameters of the carbon electrodes on the resulting biosensor characteristics is studied. The morphology of the electrodes is investigated by scanning electron microscopy, and the biosensor performance is examined by amperometric measurements of glucose (0.5–10 mM) in phosphate buffer solution, pH 7.4, at an applied potential of 1.2 V versus a Ag/AgCl reference electrode. Instead of Ecoflex, fibroin, PLA, and wound adhesive are tested as alternative encapsulation compounds: a series of swelling tests with different fibroin compositions, PLA, and Ecoflex has been performed before characterizing the most promising candidates by chronoamperometry. Therefore, the carbon electrodes are completely covered with the particular encapsulation material. Chronoamperometric measurements with H2O2 concentrations between 0.5 and 10 mM enable studying the leakage current behavior.
KW  - amperometric biosensors
KW  - biocompatible
KW  - biodegradabl
KW  - encapsulation materials
KW  - fibroin
Y1  - 2023
U6  - https://doi.org/10.1002/pssa.202300081
SN  - 1862-6300 (Print)
SN  - 1862-6319 (Online)
N1  - Corresponding author: Michael J. Schöning
VL  - 220
IS  - 22
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - THES
A1  - Achtsnicht, Stefan
T1  - Multiplex-Magnetdetektion von superparamagnetischen Beads zur Identifizierung von Trinkwasserkontaminationen
N2  - Die qualitative und quantitative Detektion von Zielsubstanzen innerhalb einer wässrigen Probe ist für viele Fragestellungen von Interesse, etwa bei der Detektion von Kontaminationen in Trinkwasser in Krisensituationen. Hierbei ist es nicht nur wichtig, dass Pathogene möglichst sensitiv detektiert werden können, sondern auch, dass die Analyse schnell erfolgt, um Betroffenen im Katastrophenfall zügig sicheres Trinkwasser zu Verfügung stellen zu können. Da bei einem solchen Szenario nicht von einer in der Nähe befindlichen funktionierenden Laborinfrastruktur ausgegangen werden kann, ist es wichtig, dass die Messung direkt vor Ort erfolgen kann. Im Rahmen dieser Arbeit wurde untersucht, ob eine derartige Schnellanalytik mithilfe von superparamagnetischen Beads (MBs) und der magnetischen Frequenzmischtechnik möglich ist. Dabei werden die MBs mit Hilfe von primären Antikörpern an die Zielsubstanz gebunden und mit sekundären Antikörpern an die Poren-Oberfläche eines Polyethylen-Filters fixiert (Sandwich-Immunoassay). So kann die Quantifizierung der Zielsubstanz auf eine magnetische Messung der immobilisierten MB-Marker zurückgeführt werden. Die magnetische Frequenzmischtechnik basiert auf der Anregung der Probe mit Magnetfeldern zweier verschiedener Frequenzen. Die durch die nichtlineare Magnetisierungsform der superparamagnetischen MBs entstehenden Mischfrequenzen werden typischerweise mithilfe einer zweistufigen Lock-in-Detektion analysiert (analoge Demodulation), die in einem Magnetreader als Handheldgerät realisiert wurde. Zusätzlich zu dieser Technik wurde das Prinzip der direkten Digitalisierung des gesamten Antwortsignals mit anschließender Fourier-Analyse der erzeugten Mischfrequenzen experimentell umgesetzt, um die Amplituden und Phasen mehrerer Mischfrequenzen simultan zu erfassen. Eine Möglichkeit zur Sensitivitätssteigerung ist die magnetische Aufkonzentration, indem vor der magnetischen Analyse eine Separation der MBs aus einem größeren Probenvolumen mittels magnetischem Feldgradienten durchgeführt wird. Zur Charakterisierung verschiedener kommerzieller MBs hinsichtlich ihrer magnetischen Separierbarkeit wurde ein Aufbau zur Messung ihrer magnetophoretischen Beweglichkeiten realisiert und ihre Geschwindigkeiten im Gradientenfeld mikroskopisch gemessen.Da eine Probe oftmals nicht nur auf eine einzige Zielsubstanz, sondern simultan auf mehrere verschiedene Pathogene hin untersucht werden soll, wurden verschiedene Ansätze entwickelt und getestet, die einen solchen multiparametrischen magnetischen Immunoassay ermöglichen. Einerseits wurde eine räumliche Separation der Bindungsbereiche für verschiedene Zielsubstanzen realisiert, die sequentiell ausgewertet werden können. Andererseits wurde die Unterscheidung von verschiedenen Zielsubstanzen anhand der Charakteristika der an sie gebundenen, verschieden funktionalisierten MB-Typen untersucht. Für eine solche Unterscheidung wurde zum einen die Anregefrequenz der magnetischen Frequenzmischtechnik während einer Messung variiert. Damit konnte gezeigt werden, dass sich verschiedene MB-Sorten anhand der Phase ihrer Frequenzmischsignale voneinander unterscheiden lassen. Weiterhin wurde gezeigt, dass sich der Signalverlauf einer binären Mischung zweier verschiedener MB-Typen als gradueller Übergang der Verläufe der beiden reinen MB-Lösungen ergibt. Eine weitere Analysemethode für einen multiparametrischen Immunoassay besteht darin, ein zusätzliches einstellbares statisches magnetisches Offsetfeld zu verwenden. Hierfür wurden mehrere Aufbauten auf Basis von Permanent- und Elektromagneten simuliert, konstruiert und charakterisiert. Mithilfe von Simulationen konnte gezeigt werden, dass eine auf diesem Verfahren beruhende Unterscheidung für MBs mit unterschiedlichen magnetischen Partikelmomenten möglich ist. Als direkte Anwendung des hier entwickelten Magnetreaders in Zusammenspiel mit der digitalen Demodulation wurde ein magnetischer Assay gegen die B-Untereinheit des Choleratoxins in Trinkwasser mit einem niedrigen Detektionslimit von 0,2 ng/ml demonstriert.
N2  - The qualitative and quantitative detection of target substances in an aqueous sample is of interest for many questions, for example in the detection of contaminations in drinking water in crisis situations. It is not only important that pathogens can be detected with highest possible sensitivity, but also that the analysis is carried out quickly so that safe drinking water can be provided in the event of a disaster. During such a scenario one cannot rely on a functioning laboratory infrastructure nearby. Therefore it is important that the measurement can be carried out directly on site. Within the scope of this work, it was investigated whether such a quick analysis can be performed using superparamagnetic beads (MBs) and the magnetic frequency mixing technique. The MBs are bound to the target substance with the aid of primary antibodies and fixed to the pore surfaces of a polyethylene filter with secondary antibodies (sandwich immunoassay). The quantification of the target substance can thus be traced back to a magnetic measurement of the immobilized MB markers. The magnetic frequency mixing technique is based on the excitation of the sample with magnetic fields of two different frequencies. The mixing frequencies generated due to the non-linear shape of the magnetization of the superparamagnetic MBs are typically analyzed using a two-stage Lock-in detection (analog demodulation), which was implemented in a magnetic reader as a handheld device. In addition to this technique, the principle of direct digitization of the entire response signal with subsequent Fourier analysis of the generated mixing frequencies was experimentally implemented in order to simultaneously record the amplitudes and phases of several mixing frequencies. One possibility for increasing the sensitivity is magnetic concentration. In that case, the MBs are separated from a larger sample volume by means of a magnetic field gradient before the magnetic analysis. To characterize various commercial MBs with regard to their magnetic separability, a setup for measuring their magnetophoretic mobility was implemented and their velocities in the gradient field were measured with an optical microscope.Often, a sample has to be examined not only for a single target substance, but for several different pathogens simultaneously. Various approaches have been developed and tested which enable such a multiparametric magnetic immunoassay. On the one hand, a spatial separation of the binding areas for different target substances was realized, which can be evaluated sequentially. On the other hand, a distinction among different target substances based on the magnetic characteristics of their attached different MB types was examined. For this discrimination, the excitation frequency of the magnetic frequency mixing technology was varied during measurement. It is shown that different MB types can be distinguished from one another based on the phase of their frequency mixing signals. The signal curve of a binary mixture of two different MB types is obtained as a gradual transition of the curves of the two pure MB solutions. Another method of analysis for a multiparametric immunoassay is based on an additional adjustable static magnetic offset field. For this purpose, several setups based on permanent magnets and electromagnets were simulated, designed and characterized. The simulations show that a distinction based on this method is possible for MBs with different magnetic particle moments. As a direct application of the developed magnetic reader in conjunction with digital demodulation, a magnetic assay against the B subunit of cholera toxin in drinking water was demonstrated, and a low detection limit of 0.2 ng/ml was achieved.
KW  - Choleratoxin B
KW  - Trinkwassersicherheit
KW  - cholera toxin B
KW  - drinking water safety
KW  - magnetic frequency mixing technique
Y1  - 2020
U6  - https://doi.org/10.18154/RWTH-2020-12052
N1  - Dissertation, RWTH Aachen University, 2020
ER  - 
TY  - JOUR
A1  - Karschuck, Tobias
A1  - Poghossian, Arshak
A1  - Ser, Joey
A1  - Tsokolakyan, Astghik
A1  - Achtsnicht, Stefan
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Capacitive model of enzyme-modified field-effect biosensors: Impact of enzyme coverage
JF  - Sensors and Actuators B: Chemical
N2  - Electrolyte-insulator-semiconductor capacitors (EISCAP) belong to field-effect sensors having an attractive transducer architecture for constructing various biochemical sensors. In this study, a capacitive model of enzyme-modified EISCAPs has been developed and the impact of the surface coverage of immobilized enzymes on its capacitance-voltage and constant-capacitance characteristics was studied theoretically and experimentally. The used multicell arrangement enables a multiplexed electrochemical characterization of up to sixteen EISCAPs. Different enzyme coverages have been achieved by means of parallel electrical connection of bare and enzyme-covered single EISCAPs in diverse combinations. As predicted by the model, with increasing the enzyme coverage, both the shift of capacitance-voltage curves and the amplitude of the constant-capacitance signal increase, resulting in an enhancement of analyte sensitivity of the EISCAP biosensor. In addition, the capability of the multicell arrangement with multi-enzyme covered EISCAPs for sequentially detecting multianalytes (penicillin and urea) utilizing the enzymes penicillinase and urease has been experimentally demonstrated and discussed.
KW  - Field-effect biosensor
KW  - Capacitive model
KW  - Enzyme coverage
KW  - Multianalyte detection
KW  - Penicillin
Y1  - 2024
U6  - https://doi.org/10.1016/j.snb.2024.135530
SN  - 0925-4005 (Print)
SN  - 1873-3077 (Online)
N1  - Corresponding Author: Michael J. Schöning
VL  - 408
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Molinnus, Denise
A1  - Janus, Kevin Alexander
A1  - Fang, Anyelina C.
A1  - Drinic, Aleksander
A1  - Achtsnicht, Stefan
A1  - Köpf, Marius
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Thick-film carbon electrode deposited onto a biodegradable fibroin substrate for biosensing applications
JF  - Physica status solidi (a)
N2  - This study addresses a proof-of-concept experiment with a biocompatible screen-printed carbon electrode deposited onto a biocompatible and biodegradable substrate, which is made of fibroin, a protein derived from silk of the Bombyx mori silkworm. To demonstrate the sensor performance, the carbon electrode is functionalized as a glucose biosensor with the enzyme glucose oxidase and encapsulated with a silicone rubber to ensure biocompatibility of the contact wires. The carbon electrode is fabricated by means of thick-film technology including a curing step to solidify the carbon paste. The influence of the curing temperature and curing time on the electrode morphology is analyzed via scanning electron microscopy. The electrochemical characterization of the glucose biosensor is performed by amperometric/voltammetric measurements of different glucose concentrations in phosphate buffer. Herein, systematic studies at applied potentials from 500 to 1200 mV to the carbon working electrode (vs the Ag/AgCl reference electrode) allow to determine the optimal working potential. Additionally, the influence of the curing parameters on the glucose sensitivity is examined over a time period of up to 361 days. The sensor shows a negligible cross-sensitivity toward ascorbic acid, noradrenaline, and adrenaline. The developed biocompatible biosensor is highly promising for future in vivo and epidermal applications.
KW  - biocompatible materials
KW  - biodegradable electronic devices
KW  - biosensors
KW  - carbon electrodes
KW  - glucose
Y1  - 2022
U6  - https://doi.org/10.1002/pssa.202200100
SN  - 1862-6319
N1  - Corresponding author: Michael J. Schöning
VL  - 219
IS  - 23
SP  - 1
EP  - 9
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Özsoylu, Dua
A1  - Kizildag, Sefa
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Differential chemical imaging of extracellular acidification within microfluidic channels using a plasma-functionalized light-addressable potentiometric sensor (LAPS)
JF  - Physics in Medicine
N2  - Extracellular acidification is a basic indicator for alterations in two vital metabolic pathways: glycolysis and cellular respiration. Measuring these alterations by monitoring extracellular acidification using cell-based biosensors such as LAPS plays an important role in studying these pathways whose disorders are associated with numerous diseases including cancer. However, the surface of the biosensors must be specially tailored to ensure high cell compatibility so that cells can represent more in vivo-like behavior, which is critical to gain more realistic in vitro results from the analyses, e.g., drug discovery experiments. In this work, O2 plasma patterning on the LAPS surface is studied to enhance surface features of the sensor chip, e.g., wettability and biofunctionality. The surface treated with O2 plasma for 30 s exhibits enhanced cytocompatibility for adherent CHO–K1 cells, which promotes cell spreading and proliferation. The plasma-modified LAPS chip is then integrated into a microfluidic system, which provides two identical channels to facilitate differential measurements of the extracellular acidification of CHO–K1 cells. To the best of our knowledge, it is the first time that extracellular acidification within microfluidic channels is quantitatively visualized as differential (bio-)chemical images.
Y1  - 2020
U6  - https://doi.org/10.1016/j.phmed.2020.100030
SN  - 2352-4510
VL  - 10
IS  - 100030
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Engelmann, Ulrich M.
A1  - Pourshahidi, Mohammad Ali
A1  - Shalaby, Ahmed
A1  - Krause, Hans-Joachim
T1  - Probing particle size dependency of frequency mixing magnetic detection with dynamic relaxation simulation
JF  - Journal of Magnetism and Magnetic Materials
N2  - Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles’ magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning  nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing.
Y1  - 2022
U6  - https://doi.org/10.1016/j.jmmm.2022.169965
SN  - 0304-8853
VL  - 563
IS  - In progress, Art. No. 169965
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Achtsnicht, Stefan
A1  - Tödter, Julia
A1  - Niehues, Julia
A1  - Telöken, Matthias
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
A1  - Schröper, Florian
T1  - 3D printed modular immunofiltration columns for frequency mixing-based multiplex magnetic immunodetection
JF  - Sensors
N2  - For performing point-of-care molecular diagnostics, magnetic immunoassays constitute a promising alternative to established enzyme-linked immunosorbent assays (ELISA) because they are fast, robust and sensitive. Simultaneous detection of multiple biomolecular targets from one body fluid sample is desired. The aim of this work is to show that multiplex magnetic immunodetection based on magnetic frequency mixing by means of modular immunofiltration columns prepared for different targets is feasible. By calculations of the magnetic response signal, the required spacing between the modules was determined. Immunofiltration columns were manufactured by 3D printing and antibody immobilization was performed in a batch approach. It was shown experimentally that two different target molecules in a sample solution could be individually detected in a single assaying step with magnetic measurements of the corresponding immobilization filters. The arrangement order of the filters and of a negative control did not influence the results. Thus, a simple and reliable approach to multi-target magnetic immunodetection was demonstrated.
Y1  - 2019
U6  - https://doi.org/10.3390/s19010148
SN  - 1424-8220
VL  - 19
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Aliazizi, Fereshteh
A1  - Özsoylu, Dua
A1  - Bakhshi Sichani, Soroush
A1  - Khorshid, Mehran
A1  - Glorieux, Christ
A1  - Robbens, Johan
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
T1  - Development and Calibration of a Microfluidic, Chip-Based Sensor System for Monitoring the Physical Properties of Water Samples in Aquacultures
JF  - Micromachines
N2  - In this work, we present a compact, bifunctional chip-based sensor setup that measures the temperature and electrical conductivity of water samples, including specimens from rivers and channels, aquaculture, and the Atlantic Ocean. For conductivity measurements, we utilize the impedance amplitude recorded via interdigitated electrode structures at a single triggering frequency. The results are well in line with data obtained using a calibrated reference instrument. The new setup holds for conductivity values spanning almost two orders of magnitude (river versus ocean water) without the need for equivalent circuit modelling. Temperature measurements were performed in four-point geometry with an on-chip platinum RTD (resistance temperature detector) in the temperature range between 2 °C and 40 °C, showing no hysteresis effects between warming and cooling cycles. Although the meander was not shielded against the liquid, the temperature calibration provided equivalent results to low conductive Milli-Q and highly conductive ocean water. The sensor is therefore suitable for inline and online monitoring purposes in recirculating aquaculture systems.
KW  - chip-based sensor setup
KW  - aquaculture
KW  - microfluidics
KW  - impedance spectroscopy
KW  - thermometry
KW  - electrical conductivity of liquids
Y1  - 2024
U6  - https://doi.org/10.3390/mi15060755
SN  - 2072-666X
N1  - This article belongs to the Special Issue "Multisensor Arrays"
N1  - Corresponding author: Michael J. Schöning
VL  - 15
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Abulnaga, El-Hussiny
A1  - Pinkenburg, Olaf
A1  - Schiffels, Johannes
A1  - E-Refai, Ahmed
A1  - Buckel, Wolfgang
A1  - Selmer, Thorsten
T1  - Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli
JF  - Journal of bacteriology
Y1  - 2013
SN  - 1098-5530 [E-Journal]
SN  - 0021-9193 [Print]
VL  - 195
IS  - 16
SP  - 3704
EP  - 3713
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Jessing, Max P.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of PCR-Amplified Tuberculosis DNA Fragments with Polyelectrolyte-Modified Field-Effect Sensors
JF  - Analytical Chemistry
N2  - Field-effect-based electrolyte-insulator-semiconductor (EIS) sensors were modified with a bilayer of positively charged weak polyelectrolyte (poly(allylamine hydrochloride) (PAH)) and probe single-stranded DNA (ssDNA) and are used for the detection of complementary single-stranded target DNA (cDNA) in different test solutions. The sensing mechanism is based on the detection of the intrinsic molecular charge of target cDNA molecules after the hybridization event between cDNA and immobilized probe ssDNA. The test solutions contain synthetic cDNA oligonucleotides (with a sequence of tuberculosis mycobacteria genome) or PCR-amplified DNA (which origins from a template DNA strand that has been extracted from Mycobacterium avium paratuberculosis-spiked human sputum samples), respectively. Sensor responses up to 41 mV have been measured for the test solutions with DNA, while only small signals of ∼5 mV were detected for solutions without DNA. The lower detection limit of the EIS sensors was ∼0.3 nM, and the sensitivity was ∼7.2 mV/decade. Fluorescence experiments using SybrGreen I fluorescence dye support the electrochemical results.
Y1  - 2018
U6  - https://doi.org/10.1021/acs.analchem.8b01807
SN  - 0003-2700
VL  - 90
IS  - 12
SP  - 7747
EP  - 7753
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Jildeh, Zaid B.
A1  - Oberländer, Jan
A1  - Kirchner, Patrick
A1  - Keusgen, Michael
A1  - Wagner, Patrick H.
A1  - Schöning, Michael Josef
T1  - Experimental and Numerical Analyzes of a Sensor Based on Interdigitated Electrodes for Studying Microbiological Alterations
JF  - physica status solidi (a): applications and materials science
N2  - In this work, a cell-based biosensor to evaluate the sterilization efficacy of hydrogen peroxide vapor sterilization processes is characterized. The transducer of the biosensor is based on interdigitated gold electrodes fabricated on an inert glass substrate. Impedance spectroscopy is applied to evaluate the sensor behavior and the alteration of test microorganisms due to the sterilization process. These alterations are related to changes in relative permittivity and electrical conductivity of the bacterial spores. Sensor measurements are conducted with and without bacterial spores (Bacillus atrophaeus), as well as after an industrial sterilization protocol. Equivalent two-dimensional numerical models based on finite element method of the periodic finger structures of the interdigitated gold electrodes are designed and validated using COMSOL® Multiphysics software by the application of known dielectric properties. The validated models are used to compute the electrical properties at different sensor states (blank, loaded with spores, and after sterilization). As a final result, we will derive and tabulate the frequency-dependent electrical parameters of the spore layer using a novel model that combines experimental data with numerical optimization techniques.
Y1  - 2018
U6  - https://doi.org/10.1002/pssa.201700920
SN  - 1862-6319
VL  - 215
IS  - 15
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Özsoylu, Dua
A1  - Kizildag, Sefa
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Effect of plasma treatment on the sensor properties of a light‐addressable potentiometric sensor (LAPS)
JF  - physica status solidi a : applications and materials sciences
N2  - A light-addressable potentiometric sensor (LAPS) is a field-effect-based (bio-) chemical sensor, in which a desired sensing area on the sensor surface can be defined by illumination. Light addressability can be used to visualize the concentration and spatial distribution of the target molecules, e.g., H+ ions. This unique feature has great potential for the label-free imaging of the metabolic activity of living organisms. The cultivation of those organisms needs specially tailored surface properties of the sensor. O2 plasma treatment is an attractive and promising tool for rapid surface engineering. However, the potential impacts of the technique are carefully investigated for the sensors that suffer from plasma-induced damage. Herein, a LAPS with a Ta2O5 pH-sensitive surface is successfully patterned by plasma treatment, and its effects are investigated by contact angle and scanning LAPS measurements. The plasma duration of 30 s (30 W) is found to be the threshold value, where excessive wettability begins. Furthermore, this treatment approach causes moderate plasma-induced damage, which can be reduced by thermal annealing (10 min at 300 °C). These findings provide a useful guideline to support future studies, where the LAPS surface is desired to be more hydrophilic by O2 plasma treatment.
Y1  - 2019
U6  - https://doi.org/10.1002/pssa.201900259
SN  - 1862-6319
N1  - Corresponding author: Torsten Wagner
VL  - 216
IS  - 20
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Pourshahidi, Ali Mohammad
A1  - Engelmann, Ulrich M.
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
T1  - Resolving ambiguities in core size determination of magnetic nanoparticles from magnetic frequency mixing data
JF  - Journal of Magnetism and Magnetic Materials
N2  - Frequency mixing magnetic detection (FMMD) has been widely utilized as a measurement technique in magnetic immunoassays. It can also be used for the characterization and distinction (also known as “colourization”) of different types of magnetic nanoparticles (MNPs) based on their core sizes. In a previous work, it was shown that the large particles contribute most of the FMMD signal. This leads to ambiguities in core size determination from fitting since the contribution of the small-sized particles is almost undetectable among the strong responses from the large ones. In this work, we report on how this ambiguity can be overcome by modelling the signal intensity using the Langevin model in thermodynamic equilibrium including a lognormal core size distribution fL(dc,d0,σ) fitted to experimentally measured FMMD data of immobilized MNPs. For each given median diameter d0, an ambiguous amount of best-fitting pairs of parameters distribution width σ and number of particles Np with R2 > 0.99 are extracted. By determining the samples’ total iron mass, mFe, with inductively coupled plasma optical emission spectrometry (ICP-OES), we are then able to identify the one specific best-fitting pair (σ, Np) one uniquely. With this additional externally measured parameter, we resolved the ambiguity in core size distribution and determined the parameters (d0, σ, Np) directly from FMMD measurements, allowing precise MNPs sample characterization.
Y1  - 2022
U6  - https://doi.org/10.1016/j.jmmm.2022.169969
SN  - 0304-8853
VL  - 563
IS  - In progress, Art. No. 169969
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rabehi, Amine
A1  - Garlan, Benjamin
A1  - Achtsnicht, Stefan
A1  - Krause, Hans-Joachim
A1  - Offenhäusser, Andreas
A1  - Ngo, Kieu
A1  - Neveu, Sophie
A1  - Graff-Dubois, Stephanie
A1  - Kokabi, Hamid
T1  - Magnetic detection structure for Lab-on-Chip applications based on the frequency mixing technique
JF  - Sensors
N2  - A magnetic frequency mixing technique with a set of miniaturized planar coils was investigated for use with a completely integrated Lab-on-Chip (LoC) pathogen sensing system. The system allows the detection and quantification of superparamagnetic beads. Additionally, in terms of magnetic nanoparticle characterization ability, the system can be used for immunoassays using the beads as markers. Analytical calculations and simulations for both excitation and pick-up coils are presented; the goal was to investigate the miniaturization of simple and cost-effective planar spiral coils. Following these calculations, a Printed Circuit Board (PCB) prototype was designed, manufactured, and tested for limit of detection, linear response, and validation of theoretical concepts. Using the magnetic frequency mixing technique, a limit of detection of 15 µg/mL of 20 nm core-sized nanoparticles was achieved without any shielding.
KW  - Lab-on-Chip
KW  - magnetic sensing
KW  - frequency mixing
KW  - superparamagnetic nanoparticles
KW  - magnetic beads
Y1  - 2018
U6  - https://doi.org/10.3390/s18061747
SN  - 1424-8220
VL  - 18
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Achtsnicht, Stefan
A1  - Neuendorf, Christian
A1  - Faßbender, Tobias
A1  - Nölke, Greta
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
A1  - Schröper, Florian
T1  - Sensitive and rapid detection of cholera toxin subunit B using magnetic frequency mixing detection
JF  - Plos One
N2  - Cholera is a life-threatening disease caused by the cholera toxin (CT) as produced by some Vibrio cholerae serogroups. In this research we present a method which directly detects the toxin’s B subunit (CTB) in drinking water. For this purpose we performed a magnetic sandwich immunoassay inside a 3D immunofiltration column. We used two different commercially available antibodies to capture CTB and for binding to superparamagnetic beads. ELISA experiments were performed to select the antibody combination. The beads act as labels for the magnetic frequency mixing detection technique. We show that the limit of detection depends on the type of magnetic beads. A nonlinear Hill curve was fitted to the calibration measurements by means of a custom-written python software. We achieved a sensitive and rapid detection of CTB within a broad concentration range from 0.2 ng/ml to more
than 700 ng/ml.
Y1  - 2019
U6  - https://doi.org/10.1371/journal.pone.0219356
SN  - 1932-6203
VL  - 14
IS  - 7
PB  - Plos
CY  - San Francisco
ER  - 
TY  - JOUR
A1  - Achtsnicht, Stefan
A1  - Schönenborn, Kristina
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
T1  - Measurement of the magnetophoretic velocity of different superparamagnetic beads
JF  - Journal of Magnetism and Magnetic Materials
N2  - The movement of magnetic beads due to a magnetic field gradient is of great interest in different application fields. In this report we present a technique based on a magnetic tweezers setup to measure the velocity factor of magnetically actuated individual superparamagnetic beads in a fluidic environment. Several beads can be tracked simultaneously in order to gain and improve statistics. Furthermore we show our results for different beads with hydrodynamic diameters between 200 and 1000 nm from diverse manufacturers. These measurement data can, for example, be used to determine design parameters for a magnetic separation system, like maximum flow rate and minimum separation time, or to select suitable beads for fixed experimental requirements.
KW  - magnetophoretic velocity
KW  - superparamagnetic bead
KW  - magnetic tweezers
KW  - magnetic separation
KW  - magnetic actuation
Y1  - 2019
U6  - https://doi.org/10.1016/j.jmmm.2018.10.066
SN  - 0304-8853
VL  - 477
IS  - 1
SP  - 244
EP  - 248
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Karschuck, Tobias
A1  - Schmidt, Stefan
A1  - Achtsnicht, Stefan
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Multiplexing system for automated characterization of a capacitive field-effect sensor array
JF  - Physica Status Solidi A
N2  - In comparison to single-analyte devices, multiplexed systems for a multianalyte detection offer a reduced assay time and sample volume, low cost, and high throughput. Herein, a multiplexing platform for an automated quasi-simultaneous characterization of multiple (up to 16) capacitive field-effect sensors by the capacitive–voltage (C–V) and the constant-capacitance (ConCap) mode is presented. The sensors are mounted in a newly designed multicell arrangement with one common reference electrode and are electrically connected to the impedance analyzer via the base station. A Python script for the automated characterization of the sensors executes the user-defined measurement protocol. The developed multiplexing system is tested for pH measurements and the label-free detection of ligand-stabilized, charged gold nanoparticles.
KW  - Capacitive field-effect sensor
KW  - Gold nanoparticles
KW  - Label-free detection
KW  - Multicell
KW  - Multiplexing
Y1  - 2023
U6  - https://doi.org/10.1002/pssa.202300265
SN  - 1862-6300 (Print)
SN  - 1862-6319 (Online)
N1  - Corresponding author: Michael Josef Schöning
VL  - 220
IS  - 22
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Achtsnicht, Stefan
A1  - Pourshahidi, Ali Mohammad
A1  - Offenhäusser, Andreas
A1  - Krause, Hans-Joachim
T1  - Multiplex detection of different magnetic beads using frequency scanning in magnetic frequency mixing technique
JF  - Sensors
N2  - In modern bioanalytical methods, it is often desired to detect several targets in one sample within one measurement. Immunological methods including those that use superparamagnetic beads are an important group of techniques for these applications. The goal of this work is to investigate the feasibility of simultaneously detecting different superparamagnetic beads acting as markers using the magnetic frequency mixing technique. The frequency of the magnetic excitation field is scanned while the lower driving frequency is kept constant. Due to the particles’ nonlinear magnetization, mixing frequencies are generated. To record their amplitude and phase information, a direct digitization of the pickup-coil’s signal with subsequent Fast Fourier Transformation is performed. By synchronizing both magnetic beads using frequency scanning in magnetic frequency mixing technique magnetic fields, a stable phase information is gained. In this research, it is shown that the amplitude of the dominant mixing component is proportional to the amount of superparamagnetic beads inside a sample. Additionally, it is shown that the phase does not show this behaviour. Excitation frequency scans of different bead types were performed, showing different phases, without correlation to their diverse amplitudes. Two commercially available beads were selected and a determination of their amount in a mixture is performed as a demonstration for multiplex measurements.
KW  - frequency mixing magnetic detection
KW  - magnetic sandwich immunoassay
KW  - multiparametric immunoassays
Y1  - 2019
U6  - https://doi.org/10.3390/s19112599
SN  - 1424-8220
VL  - 19
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Moreno, Lia
A1  - Dosev, D.
A1  - Bratov, A.
A1  - Dominguez, C.
A1  - Schöning, Michael Josef
A1  - Kloock, Joachim P.
T1  - Effect of electrical properties of the surrounding medium on the response of an interdigitated electrode array with chalcogenide glass film
T2  - XX Eurosensors : 20th anniversary ; Göteborg, Sweden, 17 - 20 September 2006 ; [proceedings]. - Vol. 1
Y1  - 2006
SN  - 978-91-631-9280-7
N1  - Paper number: T1A-P22
SP  - 384
EP  - 385
CY  - Göteborg
ER  - 
TY  - JOUR
A1  - Thust, M.
A1  - Schöning, Michael Josef
A1  - Muchandani, A.
A1  - Wang, J.
A1  - Arzdorf, Michael
A1  - Mulchandani, P.
A1  - Chen, W.
T1  - Feldeffekt-Enzymsensor zur Detektion von Pestiziden
JF  - Sensoren für zukünftige Hochtechnologien und Neuentwicklungen für die Verfahrenstechnik / 6. Dresdner Sensor-Symposium, 8. - 10. Dezember 2003, Dresden. Jörg Peter Baselt; Gerald Gerlach (Hg.)
Y1  - 2003
SN  - 3-935712-92-8
SP  - 125
EP  - 128
PB  - w.e.b.-Univ.-Verl.
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Arzdorf, Michael
A1  - Mulchandani, P.
A1  - Chen, W.
A1  - Mulchandani, A.
T1  - Towards a capacitive enzyme sensor for direct determination of organophosphorus pesticides: Fundamentals studies and aspects of development
JF  - Sensors. 3 (2003), H. 6
Y1  - 2003
SN  - 1424-8220
SP  - 119
EP  - 127
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Arzdorf, Michael
A1  - Mulchandani, P.
A1  - Chen, W.
A1  - Mulchandani, A.
T1  - A capacitive field-effect sensor for the direct determination of organophosphorus pesticides
JF  - Sensors and Actuators B. 91 (2003), H. 1-3
Y1  - 2003
SN  - 0925-4005
SP  - 92
EP  - 97
ER  - 
TY  - JOUR
A1  - Arida, Hassan A.
A1  - Al-Haddad, Ameera
A1  - Schöning, Michael Josef
T1  - New Solid-State Organic Membrane Based Lead-Selective Micro-Electrode
JF  - International Journal of Electrochemical Science. 6 (2011), H. 9
Y1  - 2011
SN  - 1452-3981
SP  - 3858
EP  - 3867
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Schusser, Sebastian
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Multi-Parametererfassung mit siliziumbasiertem Sensorchip: Aus Drei mach Eins
JF  - GIT Labor-Fachzeitschrift
Y1  - 2014
SN  - 0016-3538
IS  - 2
SP  - 28
EP  - 30
PB  - Wiley
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Berndsen, L.
A1  - Schöning, Michael Josef
T1  - Chemical sensor as a physical sensor: ISFET-based flowvelocity, flow-direction and diffusion-coefficient sensor
JF  - Book of abstracts / ed. by J. Saneistr.
Y1  - 2002
SN  - 80-01-02576-4
N1  - Eurosensors ; (16, 2002, Praha)
SP  - 649
EP  - 652
PB  - Czech Technical University, Faculty of Electrical Engineering, Department of Measurement
CY  - Prague
ER  - 
TY  - JOUR
A1  - Näther, Niko
A1  - Auger, V.
A1  - Poghossian, Arshak
A1  - Koudelka-Hep, M.
A1  - Schöning, Michael Josef
T1  - A miniaturized flow-through cell in SU-8 technique for EIS sensors
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 994
EP  - 995
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Weiland, Maryam
A1  - Schöning, Michael Josef
ED  - Lvova, Larisa
ED  - Kirsanov, Dmitry
ED  - di Natale, Corrado
ED  - Legin, Audrey
T1  - Nanoplate field-effect capacitors: a new transducer structure for multiparameter (bio-)chemical sensing
T2  - Multisensor system for chemical analysis : materials and sensors
N2  - An array of electrically isolated nanoplate field-effect silicon-on-insulator (SOI) capacitors as a new transducer structure for multiparameter (bio-)chemical sensing is presented. The proposed approach allows addressable biasing and electrical readout of multiple nanoplate field-effect capacitive (bio-)chemical sensors on the same SOI chip, as well as differential-mode measurements. The realized sensor chip has been applied for pH and penicillin concentration measurements, electrical monitoring of polyelectrolyte multilayer formation, and the label-free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization and denaturation events.
Y1  - 2014
SN  - 978-981-4411-15-8 ; 978-981-4411-16-5
U6  - https://doi.org/10.1201/b15491-11
SP  - 333
EP  - 373
PB  - Jenny Stanford Publishing
CY  - Singapore
ET  - 1
ER  - 
TY  - JOUR
A1  - Buniatyan, V.
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Aroutiounian, V. M.
A1  - Schöning, Michael Josef
T1  - BaxSr1-x TiO3/pc-Si heterojunction capacitance
JF  - Armenian journal of physics
Y1  - 2013
SN  - 1829-1171
VL  - 6
IS  - 4
SP  - 188
EP  - 197
PB  - National Academy of Sciences of Armenia
CY  - Yerevan
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
A1  - Schultze, Joachim W.
T1  - Measuring seven parameters by two ISFET modules in a microcell set-up
JF  - Int. Journal of Computational Engineering Science. 4 (2003), H. 2
Y1  - 2003
SN  - 1465-8763
SP  - 257
EP  - 260
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Reisert, Steffen
A1  - Kramer, Friederike
A1  - Begoyan, Vardges K.
A1  - Buniatyan, Vahe V.
A1  - Schöning, Michael Josef
T1  - Multi-parameter sensing using high-k oxide of barium strontium titanate
JF  - Physica status solidi (a)
N2  - High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors. In this work, a Si-based sensor chip containing Pt interdigitated electrodes covered with a thin BST layer (485 nm) has been developed for multi-parameter chemical sensing. The chip has been applied for the contactless measurement of the electrolyte conductivity, the detection of adsorbed charged macromolecules (positively charged polyelectrolytes of polyethylenimine) and the concentration of hydrogen peroxide (H2O2) vapor. The experimental results of functional testing of individual sensors are presented. The mechanism of the BST sensitivity to charged polyelectrolytes and H2O2 vapor has been proposed and discussed.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431911
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1259
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Aboulnaga, Elhussiny A.
A1  - Zou, Huibin
A1  - Selmer, Thorsten
A1  - Xian, Mo
T1  - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16
JF  - Journal of Biotechnology
N2  - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate.
Y1  - 2018
U6  - https://doi.org/10.1016/j.jbiotec.2018.03.007
SN  - 0168-1656
VL  - 274
SP  - 15
EP  - 27
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Iken, Heiko
A1  - Ahlborn, Kristina
A1  - Gerlach, Frank
A1  - Vonau, Winfried
A1  - Zander, Wilhelm
A1  - Schubert, Jürgen P.
A1  - Schöning, Michael Josef
T1  - Development of redox glasses and subsequent processing by means of pulsed laser deposition for realizing silicon-based thin-film sensors
JF  - Electrochimica acta
Y1  - 2013
SN  - 1873-3859 (E-Journal); 0013-4686 (Print)
SP  - Available online 30.8.2013
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Grinsven, Bart van
A1  - Vanden Bon, Natalie
A1  - Grieten, Lars
A1  - Murib, Mohammed Sharif
A1  - Janssen, Stoffel Dominique
A1  - Haenen, Ken
A1  - Schneider, E.
A1  - Ingebrandt, Sven
A1  - Schöning, Michael Josef
A1  - Vermeeren, Veronique
A1  - Ameloot, Marcel
A1  - Michiels, Luc
A1  - Thoelen, Ronald
A1  - De Ceuninck, Ward A.
A1  - Wagner, Patrick
T1  - Rapid assessment of the stability of DNA duplexes by impedimetric real-time monitoring of chemically induced denaturation
JF  - Lab on a Chip
Y1  - 2011
SN  - 1473-0197
VL  - 11
IS  - 9
SP  - 1656
EP  - 1663
PB  - Royal Society of Chemistry (RSC)
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Grinsven, B. van
A1  - Grieten, L.
A1  - Janssens, S. D.
A1  - Vermeeren, V.
A1  - Eersels, K.
A1  - Broeders, J.
A1  - Ameloot, Marcel
A1  - Michiels, L.
A1  - Ceuninck, W. De
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
T1  - Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates
JF  - Physica Status Solidi (A). Vol. 210 (2013), iss. 5
Y1  - 2013
SN  - 0031-8965
SP  - 911
EP  - 917
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Yeap, W. S.
A1  - Eurlings, Y.
A1  - Grinsven, B. van
A1  - Boyen, H.-G.
A1  - Conings, B.
A1  - Michiels, L.
A1  - Ameloot, Marcel
A1  - Carleer, R.
A1  - Warmer, J.
A1  - Kaul, P.
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Ceuninck, W. de
A1  - Wagner, P.
T1  - Heat-transfer based characterization of DNA on synthetic sapphire chips
JF  - Sensors and Actuators B: Chemical
N2  - In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.02.027
SN  - 0925-4005
VL  - 230
IS  - 230
SP  - 260
EP  - 271
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - PAT
A1  - Degering, Christian
A1  - Wieland, Susanne
A1  - Islam, Shohana
A1  - Lindner, Claudia
A1  - Siegert, Petra
A1  - Falkenberg, Fabian
A1  - Bongaerts, Johannes
T1  - Wasch- und Reinigungsmittel enthaltend Protease (aus Fictibacillus arsenicus)
N2  - Die Erfindung liegt auf dem Gebiet der Enzymtechnologie. Die Erfindung betrifft Proteasen aus Fictibacillus arsenicus, die insbesondere im Hinblick auf den Einsatz in Wasch- und Reinigungsmitteln verwendet werden können, alle hinreichend ähnlichen Proteasen mit einer entsprechend ähnlichen Sequenz zu SEQ ID NO:1 und für sie codierende Nukleinsäuren. Die Erfindung betrifft ferner deren Herstellung sowie Verfahren zur Verwendung dieser Proteasen, deren Verwendung als solche sowie diese enthaltende Mittel, insbesondere Wasch- und Reinigungsmittel.
Y1  - 2024
ER  - 
TY  - PAT
A1  - Degering, Christian
A1  - Wieland, Susanne
A1  - Islam, Shohana
A1  - Lindner, Claudia
A1  - Bongaerts, Johannes
A1  - Siegert, Petra
A1  - Falkenberg, Fabian
T1  - Wasch- und Reinigungsmittel enthaltend Protease (aus Metabacillus indicus)
N2  - Die Erfindung liegt auf dem Gebiet der Enzymtechnologie. Die Erfindung betrifft Proteasen aus Metabacillus indicus, die insbesondere im Hinblick auf den Einsatz in Wasch- und Reinigungsmitteln verwendet werden können, alle hinreichend ähnlichen Proteasen mit einer entsprechend ähnlichen Sequenz zu SEQ ID NO:1 und für sie codierende Nukleinsäuren. Die Erfindung betrifft ferner deren Herstellung sowie Verfahren zur Verwendung dieser Proteasen, deren Verwendung als solche sowie diese enthaltende Mittel, insbesondere Wasch- und Reinigungsmittel.
Y1  - 2024
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Bäcker, Matthias
T1  - Chip-basierte Sensoren für die Biotechnik
Y1  - 2012
SN  - 1611-0854
VL  - 13
IS  - 2
PB  - BIOCOM
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Kirchner, Patrick
A1  - Henkel, H.
A1  - Näther, Niko
A1  - Spelthahn, H.
A1  - Schneider, A.
A1  - Berger, Jörg
A1  - Kolstad, J.
A1  - Friedrich, P.
A1  - Schöning, Michael Josef
T1  - RFID-basiertes Sensorsystem zur Realisierung intelligenter Verpackungen für die Nahrungsmittelindustrie
T2  - KMU - innovativ: IKT 2008. CD-ROM : BMBF-Statustagung KMU - innovativ: IKT, Darmstadt, 17. - 18. Nov. 2008
Y1  - 2008
IS  - CD-ROM-Ausg.
PB  - BMBF
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Reisert, Steffen
A1  - Henkel, H.
A1  - Schneider, A.
A1  - Schäfer, Daniel
A1  - Friedrich, P.
A1  - Berger, Jörg
A1  - Schöning, Michael Josef
T1  - Entwicklung eines Handheld-Sensorsystems für die „On-line“-Messung der H2O2-Konzentration in aseptischen Entkeimungsprozessen
JF  - 9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]
Y1  - 2009
SN  - 978-3-941298-44-6
N1  - Dresdner Sensor-Symposium ; (9, 2009, Dresden)
SP  - 285
EP  - 288
PB  - TUDpress
CY  - Dresden
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Leinhos, Marcel
A1  - Schöning, Michael Josef
T1  - Real-time in-situ electrical monitoring of the degradation of biopolymers using semiconductor field-effect devices
T2  - Biodegradable biopolymers. Vol. 1
Y1  - 2015
SN  - 978-1-63483-632-6
SP  - 135
EP  - 153
PB  - Nova Science Publ.
CY  - Hauppauge
ER  - 
TY  - CHAP
A1  - Beging, Stefan
A1  - Poghossian, Arshak
A1  - Mlynek, D.
A1  - Hataihimakul, S.
A1  - Pedraza, A.
A1  - Dhawan, S.
A1  - Laube, N.
A1  - Kleinen, Lisa
A1  - Baldsiefen, Gerhard
A1  - Busch, Heinrich von
A1  - Schöning, Michael Josef
T1  - Ion-selective sensors for the determination of the risk of urinary stone formation
T2  - Micro- and Nanosystems in biochemical diagnosis : Principles and applications
Y1  - 2010
SP  - 74
EP  - 80
CY  - Warsaw
ER  - 
TY  - JOUR
A1  - Beging, Stefan
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Hataihimakul, Sudkanung
A1  - Busch, Heinz
A1  - Baldsiefen, Gerhard
A1  - Laube, N.
A1  - Kleinen, Lisa
A1  - Hosseiny, Reyhaneh
T1  - Feldeffektbasierender Ca2+-sensitiver Sensor für den Einsatz im Nativurin zur Bestimmung des Harnsteinbildungsrisikos
JF  - Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. März 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik
Y1  - 2008
SN  - 978-3-18-092011-5
N1  - VDI-Berichte ; 2011 ; Sensoren und Messsysteme 2008, 14. GMA/ITG-Fachtagung, VDI/VDE- Gesellschaft Mess- und Automatisierungstechnik, + CD-ROM, Ludwigsburg, DE, 11.-12. Mar, 2008
SP  - 775
EP  - 782
PB  - VDI-Verl.
CY  - Düsseldorf
ER  - 
TY  - JOUR
A1  - Spelthahn, Heiko
A1  - Schaffrath, Sophie
A1  - Coppe, Thomas
A1  - Rufi, Frederic
A1  - Schöning, Michael Josef
T1  - Development of an electrolyte-insulator-semiconductor (EIS) based capacitive heavy metal sensor for the detection of Pb2+ und Cd2+ ions
JF  - Physica status solidi (a) : applications and material science
N2  - Chalcogenide glass materials as membranes for potentiometric sensors for chemical analysis in solutions have been studied since more than 20 years. In this work, an electrolyte–insulator–semiconductor structure was combined with chalcogenide glass membranes prepared by means of the pulsed laser deposition technique. Depending on the membrane composition a selectivity to different ions (Cd2+ and Pb2+) is achieved. The different sensor membranes have been physically characterised using microscopy, ellipsometry, profilometry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and Rutherford backscattering spectrometry (RBS). The electrochemical behaviour has been investigated via capacitance/voltage (C/V) and constant capacitance (ConCap) measurements and results in a Cd2+ sensitivity of 23.1 ± 0.6 mV per decade in a linear range from 7 × 10−6 to 10−2 mol/l and 24.4 ± 0.5 mV per decade in a linear range from 5 × 10−6 to 10−2 mol/l for Pb2+, respectively.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983306
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 930
EP  - 934
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Werner, Frederik
A1  - Miyamoto, Ko-ichiro
A1  - Ackermann, Hans-Josef
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - FPGA-based LAPS device for the flexible design of sensing sites on functional interfaces
JF  - Physica Status Solidi (A)
N2  - The development of new interfaces for (bio-)chemical sensors requires comprehensive analyses and testing. The light-addressable potentiometric sensor (LAPS) can be used as a platform to investigate the sensitivity of a newly developed interface towards (bio-)chemical agents. LAPS measurements are spatially resolved by utilisation of focused light beams to define individual measurement spots. In this work, a new digitally modulated LAPS set-up based on an FPGA design will be introduced to increase the number of measurement spots, to shorten the measurement time and to improve the measurement accuracy.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983320
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 844
EP  - 849
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Abouzar, Maryam H.
A1  - Wenmackers, Sylvia
A1  - Janssens, Stoffel D.
A1  - Haenen, Ken
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Capacitive field-effect (bio-)chemical sensors based on nanocrystalline diamond films
JF  - MRS Online Proceedings Library
N2  - Capacitive field-effect electrolyte-diamond-insulator-semiconductor (EDIS) structures with O-terminated nanocrystalline diamond (NCD) as sensitive gate material have been realized and investigated for the detection of pH, penicillin concentration, and layer-by-layer adsorption of polyelectrolytes. The surface oxidizing procedure of NCD thin films as well as the seeding and NCD growth process on a Si-SiO2 substrate have been improved to provide high pH-sensitive, non-porous thin films without damage of the underlying SiO2 layer and with a high coverage of O-terminated sites. The NCD surface topography, roughness, and coverage of the surface groups have been characterized by SEM, AFM and XPS methods. The EDIS sensors with O-terminated NCD film treated in oxidizing boiling mixture for 45 min show a pH sensitivity of about 50 mV/pH. The pH-sensitive properties of the NCD have been used to develop an EDIS-based penicillin biosensor with high sensitivity (65-70 mV/decade in the concentration range of 0.25-2.5 mM penicillin G) and low detection limit (5 μM). The results of label-free electrical detection of layer-by-layer adsorption of charged polyelectrolytes are presented, too.
Y1  - 2010
SN  - 1946-4274
VL  - 1203
PB  - MRS
CY  - Warrendale
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Koch, Claudia
A1  - Eiben, Sabine
A1  - Geiger, Fania
A1  - Eber, Fabian
A1  - Gliemann, Hartmut
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Tobacco mosaic virus as enzyme nanocarrier for electrochemical biosensors
JF  - Sensors and Actuators B: Chemical
N2  - The conjunction of (bio-)chemical recognition elements with nanoscale biological building blocks such as virus particles is considered as a very promising strategy for the creation of biohybrids opening novel opportunities for label-free biosensing. This work presents a new approach for the development of biosensors using tobacco mosaic virus (TMV) nanotubes or coat proteins (CPs) as enzyme nanocarriers. Sensor chips combining an array of Pt electrodes loaded with glucose oxidase (GOD)-modified TMV nanotubes or CP aggregates were used for amperometric detection of glucose as a model system for the first time. The presence of TMV nanotubes or CPs on the sensor surface allows binding of a high amount of precisely positioned enzymes without substantial loss of their activity, and may also ensure accessibility of their active centers for analyte molecules. Specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CPs was achieved via bioaffinity binding. These layouts were tested in parallel with glucose sensors with adsorptively immobilized [SA]-GOD, as well as [SA]-GOD crosslinked with glutardialdehyde, and came out to exhibit superior sensor performance. The achieved results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for future applications in biosensorics and biochips.
Y1  - 2017
U6  - https://doi.org/10.1016/j.snb.2016.07.096
SN  - 0925-4005
VL  - 238
SP  - 716
EP  - 722
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Koch, Claudia
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Schöning, Michael Josef
ED  - Wege, Christina
T1  - TMV-Based Adapter Templates for Enhanced Enzyme Loading in Biosensor Applications
T2  - Virus-Derived Nanoparticles for Advanced Technologies
N2  - Nanotubular tobacco mosaic virus (TMV) particles and RNA-free lower-order coat protein (CP) aggregates have been employed as enzyme carriers in different diagnostic layouts and compared for their influence on biosensor performance. In the following, we describe a label-free electrochemical biosensor for improved glucose detection by use of TMV adapters and the enzyme glucose oxidase (GOD). A specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CP aggregates was achieved via bioaffinity binding. Glucose sensors with adsorptively immobilized [SA]-GOD, and with [SA]-GOD cross-linked with glutardialdehyde, respectively, were tested in parallel on the same sensor chip. Comparison of these sensors revealed that TMV adapters enhanced the amperometric glucose detection remarkably, conveying highest sensitivity, an extended linear detection range and fastest response times. These results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for applications in biosensorics and biochips. Here, we describe the fabrication and use of amperometric sensor chips combining an array of circular Pt electrodes, their loading with GOD-modified TMV nanotubes (and other GOD immobilization methods), and the subsequent investigations of the sensor performance.
KW  - Tobacco mosaic virus (TMV)
KW  - Coat protein
KW  - Enzyme nanocarrier
KW  - Glucose biosensor
KW  - Glucose oxidase
Y1  - 2018
SN  - 978-1-4939-7808-3
U6  - https://doi.org/10.1007/978-1-4939-7808-3
N1  - Methods in Molecular Biology, vol 1776
SP  - 553
EP  - 568
PB  - Humana Press
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Koch, Claudia
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Wege, Christian
T1  - Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors
JF  - Nanotheranostics
N2  - The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts.
Y1  - 2018
U6  - https://doi.org/10.7150/ntno.22114
SN  - 2206-7418
VL  - 2
IS  - 2
SP  - 184
EP  - 196
PB  - Ivyspring
CY  - Sydney
ER  - 
TY  - CHAP
A1  - Jablonski, Melanie
A1  - Koch, Claudia
A1  - Bronder, Thomas
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Field-Effect Biosensors Modified with Tobacco Mosaic Virus Nanotubes as Enzyme Nanocarrier
T2  - MDPI Proceeding
Y1  - 2017
U6  - https://doi.org/10.3390/proceedings1040505
N1  - Eurosensors 2017 Conference, Paris, France, 3–6 September 2017
VL  - 1
IS  - 4
ER  - 
TY  - JOUR
A1  - Beging, Stefan
A1  - Mlynek, Daniela
A1  - Hataihimakul, Sudkanung
A1  - Poghossian, Arshak
A1  - Baldsiefen, Gerhard
A1  - Busch, Heinz
A1  - Laube, Norbert
A1  - Kleinen, Lisa
A1  - Schöning, Michael Josef
T1  - Field-effect calcium sensor for the determination of the risk of urinary stone  formation
JF  - Sensors and Actuators B: Chemical
N2  - Urinary stone formation has been evolved to a widespread disease during the last years. The reason for the formation of urinary stones are little crystals, mostly composed of calcium oxalate, which are formed in human kidneys. The early diagnosis of the risk for urinary stone formation of patients can be determined by the “Bonn-Risk-Index” method based on the potentiometric detection of the Ca2+-ion concentration and an optical determination of the triggered crystallisation of calcium oxalate in unprocessed urine. In this work, miniaturised capacitive field-effect EMIS (electrolyte-membrane-insulator-semiconductor) sensors have been developed for the determination of the Ca2+-ion concentration in human native urine. The Ca2+-sensitive EMIS sensors have been systematically characterised by impedance spectroscopy, capacitance–voltage and constant–capacitance method in terms of sensitivity, signal stability and response time in both CaCl2 solutions and in native urine. The obtained results demonstrate the suitability of EMIS sensors for the measurement of the Ca2+-ion concentration in native urine of patients.
Y1  - 2010
U6  - https://doi.org/10.1016/j.snb.2008.12.012
SN  - 0925-4005
N1  - 22nd International Conference on Eurosensors: Dresden, Germany, 7-10 September 2008
VL  - 144
IS  - 2
SP  - 374
EP  - 379
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Reisert, Steffen
A1  - Henkel, Hartmut
A1  - Schneider, Andreas
A1  - Schäfer, Daniel
A1  - Friedrich, Peter
A1  - Berger, Jörg
A1  - Schöning, Michael Josef
T1  - Development of a handheld sensor system for the online measurement of hydrogen peroxide in aseptic filling systems
JF  - Physica Status Solidi (A)
N2  - A handheld sensor system for the online measurement of hydrogen peroxide (H2O2) in aseptic sterilisation processes has been developed. It is based on a calorimetric-type gas sensor that consists of a differential set-up of two temperature sensors, of which one is catalytically activated and the second one is passivated and used as reference. The sensor principle relies in detecting a rise in temperature on the active sensor due to the exothermic reaction of H2O2 on the catalytic surface. To characterise the sensor system towards H2O2 sensitivity and other influencing factors, measurements have been carried out both at an experimental set-up and a manufacturer's sterilisation machine. Physical sensor characterisation was done by means of the optical microscopy.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983304
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 913
EP  - 918
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Sugawara, Yuri
A1  - Kanoh, Shin´ichiro
A1  - Yoshinobu, Tatsuo
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Image correction method for the chemical imaging sensor
JF  - Sensors and Actuators B: Chemical
N2  - The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the spatial distribution of chemical species. For the practical application of this sensor, artifacts in the chemical images due to defects of the semiconductor substrate and contamination of the sensing surface etc. have been a major problem. An image correction method was developed to eliminate the influence of nonuniformity of individual sensor plate.
Y1  - 2010
U6  - https://doi.org/10.1016/j.snb.2008.10.069
SN  - 0925-4005
N1  - 22nd International Conference on Eurosensors: Dresden, Germany, 7-10 September 2008
VL  - 144
IS  - 2
SP  - 344
EP  - 348
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Siqueira, José R. Jr.
A1  - Oliveira, Osvaldo N. Jr.
A1  - Moritz, Werner
A1  - Schöning, Michael Josef
T1  - Capacitive electrolyte-insulator-semiconductor structures functionalised with a polyelectrolyte/enzyme multilayer: New strategy for enhanced field-effect biosensing
JF  - Physica Status Solidi (A)
N2  - A novel strategy for enhanced field-effect biosensing using capacitive electrolyte–insulator–semiconductor (EIS) structures functionalised with pH-responsive weak polyelectrolyte/enzyme or dendrimer/enzyme multilayers is presented. The feasibility of the proposed approach is exemplarily demonstrated by realising a penicillin biosensor based on a capacitive p-Si–SiO2 EIS structure functionalised with a poly(allylamine hydrochloride) (PAH)/penicillinase and a poly(amidoamine) dendrimer/penicillinase multilayer. The developed sensors response to changes in both the local pH value near the gate surface and the charge of macromolecules induced via enzymatic reaction, resulting in a higher sensitivity. For comparison, an EIS penicillin biosensor with adsorptively immobilised penicillinase has been also studied. The highest penicillin sensitivity of 100 mV/dec has been observed for the EIS sensor functionalised with the PAH/penicillinase multilayer. The lower and upper detection limit was around 20 µM and 10 mM, respectively. In addition, an incorporation of enzymes in a multilayer prepared by layer-by-layer technique provides a larger amount of immobilised enzymes per sensor area, reduces enzyme leaching effects and thus, enhances the biosensor lifetime (the loss of penicillin sensitivity after 2 months was 10–12%).
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983317
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 884
EP  - 890
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Jablonski, Melanie
A1  - Koch, Claudia
A1  - Bronder, Thomas
A1  - Rolka, David
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Field-effect biosensor using virus particles as scaffolds for enzyme immobilization
JF  - Biosensors and Bioelectronics
N2  - A field-effect biosensor employing tobacco mosaic virus (TMV) particles as scaffolds for enzyme immobilization is presented. Nanotubular TMV scaffolds allow a dense immobilization of precisely positioned enzymes with retained activity. To demonstrate feasibility of this new strategy, a penicillin sensor has been developed by coupling a penicillinase with virus particles as a model system. The developed field-effect penicillin biosensor consists of an Al-p-Si-SiO₂-Ta₂O₅-TMV structure and has been electrochemically characterized in buffer solutions containing different concentrations of penicillin G. In addition, the morphology of the biosensor surface with virus particles was characterized by scanning electron microscopy and atomic force microscopy methods. The sensors possessed a high penicillin sensitivity of ~ 92 mV/dec in a nearly-linear range from 0.1 mM to 10 mM, and a low detection limit of about 50 µM. The long-term stability of the penicillin biosensor was periodically tested over a time period of about one year without any significant loss of sensitivity. The biosensor has also been successfully applied for penicillin detection in bovine milk samples.
Y1  - 2018
U6  - https://doi.org/10.1016/j.bios.2018.03.036
SN  - 0956-5663
VL  - 110
SP  - 168
EP  - 174
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Kirchner, Patrick
A1  - Ng, Yue Ann
A1  - Spelthahn, Heiko
A1  - Schneider, Andreas
A1  - Henkel, Hartmut
A1  - Friedrich, Peter
A1  - Kolstad, Jens
A1  - Berger, Jörg
A1  - Keusgen, Michael
T1  - Gas sensor investigation based on a catalytically activated thin-film thermopile for H2O2 detection
JF  - Physica Status Solidi (A)
N2  - In aseptic filling systems, hydrogen peroxide vapour is commonly used for the reduction of microbial contaminations in carton packages. In this process, the germicidal efficiency of the vapour depends especially on the H₂O₂ concentration. To monitor the H₂O₂ concentration, a calorimetric H₂O₂ gas sensor based on a catalytically activated thin-film thermopile is investigated. Two different sensor layouts, namely a circular and a linear form, as well as two various material pairs such as tungsten/nickel and gold/nickel, have been examined for the realization of a thin-film thermopile. Additionally, manganese oxide and palladium particles have been compared as responsive catalysts towards H₂O₂. The thin-film sensors have been investigated at various H₂O₂ concentrations, gas temperatures and flow rates.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983309
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 787
EP  - 792
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Chaudhuri, S.
A1  - Zander, W.
A1  - Schubert, J.
A1  - Begoyan, Vardges K.
A1  - Buniatyan, V. V.
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Capacitively coupled electrolyte-conductivity sensor based on high-k material of barium strontium titanate
JF  - Sensors and actuators. B: Chemical
Y1  - 2014
U6  - https://doi.org/10.1016/j.snb.2014.02.103
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
IS  - 198
SP  - 102
EP  - 109
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Zander, W.
A1  - Schubert, J.
A1  - Sukoyan, L. H.
A1  - Begoyan, Vardges K.
A1  - Buniatyan, V. V.
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Chemische Sensoren mit Bariumstrontiumtitanat als funktionelle Schicht zur Multiparameterdetektion
T2  - 11. Dresdner Sensor-Symposium : 9.-11.12.2013
Y1  - 2013
SN  - 978-3-9813484-5-3
SP  - 368
EP  - 372
ER  - 
TY  - JOUR
A1  - Buniatyan, Vahe V.
A1  - Abouzar, Maryam H.
A1  - Martirosyan, Norayr W.
A1  - Schubert, Jürgen
A1  - Gevorgian, Spartak
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
T1  - pH-sensitive properties of barium strontium titanate (BST) thin films prepared by pulsed laser deposition technique
JF  - Physica Status Solidi (A)
N2  - pH-sensitive properties of barium strontium titanate (BST) high-k thin films as alternative gate material for field-effect capacitive (bio-)chemical sensors based on an electrolyte-insulator-semiconductor system have been investigated. The BST films of different compositions (Ba0.31Sr0.69TiO3, Ba0.25Sr0.75TiO3 and Mg-doped Ba0.8Sr0.2Mg0.1Ti0.9O3) were deposited by pulsed laser deposition technique from targets fabricated by self-propagating high-temperature synthesis. The realised sensors have been electrochemically characterised by means of impedance-spectroscopy, capacitance–voltage and constant-capacitance method. The sensors possess a Nernstian-like pH sensitivity in the concentration range between pH 3 and 11 with a response time of 5–10 s. An equivalent circuit model for the BST-based capacitive field-effect sensor is discussed.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983310
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 824
EP  - 830
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Turek, Monik
A1  - Heiden, Wolfgang
A1  - Guo, Sharon
A1  - Riesen, Alfred
A1  - Schubert, Jürgen
A1  - Zander, Willi
A1  - Krüger, Peter
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Simultaneous detection of cyanide and heavy metals for environmental analysis by means of µISEs
JF  - Physica Status Solidi (A)
N2  - In environmental analysis, cyanide and heavy metals play an important role, because these substances are highly toxic for biological systems. They can lead to chronic and acute diseases. Due to the chemical properties of cyanide it is frequently used for industrial processes such as extraction of silver and gold. Heavy metals can be found as trace elements in nature and are often applied in industries e.g., galvanization processes. Up to now, cyanide and heavy metals can be detected by several sensors separately and their detection is often limited to laboratory investigations. In this publication, with regard to an in situ analysis, a new miniaturized silicon-based sensor system for the simultaneous detection of cyanide and heavy metals in aqueous solutions is presented that is based on chalcogenide glass-based micro ion-selective electrodes (µISEs). The µISEs are incorporated into a specially designed measuring system for the simultaneous detection of heavy metals and cyanide in solutions and validated by simultaneous measurements of Cu2+- and CN−-ions, Cd2+- and CN−- ions and Pb2+- and CN−-ions. The particular sensor system has shown good sensor properties in the µ-molar ion-concentration range. For simultaneous measurements in complex heavy metal and cyanide solutions an intelligent software using fuzzy logic is discussed.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983303
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 817
EP  - 823
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Siqueira, José R. Jr.
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Zucolotto, Valtencir
A1  - Oliveira, Osvaldo N. Jr.
A1  - Schöning, Michael Josef
T1  - Associating biosensing properties with the morphological structure of multilayers containing carbon nanotubes on field-effect devices
JF  - Physica Status Solidi (A)
N2  - The control of molecular architecture provided by the layer-by-layer (LbL) technique has led to enhanced biosensors, in which advantageous features of distinct materials can be combined. Full optimization of biosensing performance, however, is only reached if the film morphology is suitable for the principle of detection of a specific biosensor. In this paper, we report a detailed morphology analysis of LbL films made with alternating layers of single-walled carbon nanotubes (SWNTs) and polyamidoamine (PAMAM) dendrimers, which were then covered with a layer of penicillinase (PEN). An optimized performance to detect penicillin G was obtained with 6-bilayer SWNT/PAMAM LbL films deposited on p-Si-SiO2-Ta2O5 chips, used in biosensors based on a capacitive electrolyte-insulator-semiconductor (EIS) and a light-addressable potentiometric sensor (LAPS) structure, respectively. Field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) images indicated that the LbL films were porous, with a large surface area due to interconnection of SWNT into PAMAM layers. This morphology was instrumental for the adsorption of a larger quantity of PEN, with the resulting LbL film being highly stable. The experiments to detect penicillin were performed with constant-capacitance (ConCap) and constant-current (CC) measurements for EIS and LAPS sensors, respectively, which revealed an enhanced detection signal and sensitivity of ca. 100 mV/decade for the field-effect sensors modified with the PAMAM/SWNT LbL film. It is concluded that controlling film morphology is essential for an enhanced performance of biosensors, not only in terms of sensitivity but also stability and response time.
Y1  - 2010
U6  - https://doi.org/10.1002/pssa.200983301
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
VL  - 207
IS  - 4
SP  - 781
EP  - 786
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Bäcker, Matthias
A1  - Koch, Claudia
A1  - Geiger, Fania
A1  - Eber, Fabian
A1  - Gliemann, Hartmut
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - A New Class of Biosensors Based on Tobacco Mosaic Virus and Coat Proteins as Enzyme Nanocarrier
T2  - Procedia Engineering
Y1  - 2016
U6  - https://doi.org/10.1016/j.proeng.2016.11.228
SN  - 1877-7058
N1  - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary
VL  - Vol. 168
SP  - 618
EP  - 621
ER  - 
TY  - JOUR
A1  - Ribitsch, Doris
A1  - Karl, Wolfgang
A1  - Birner-Gruenberger, R.
A1  - Gruber, K.
A1  - Eiteljoerg, I.
A1  - Remler, Peter
A1  - Wieland, S.
A1  - Siegert, Petra
A1  - Maurer, Karl-Heinz
A1  - Schwab, H.
T1  - C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli
JF  - Journal of biotechnology
N2  - Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477.

This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7–11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease.
Y1  - 2010
U6  - https://doi.org/10.1016/j.jbiotec.2010.09.947
SN  - 1873-4863 (E-Journal); 0168-1656 (Print)
VL  - 150
IS  - 3
SP  - 408
EP  - 416
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Kirchner, Patrick
A1  - Spelthahn, Heiko
A1  - Schöning, Michael Josef
A1  - Henkel, Hartmut
A1  - Schneider, Andreas
A1  - Friedrich, Peter
A1  - Kolstad, Jens
A1  - Berger, Jörg
T1  - Realisierung eines Polyimid-basierten kalorimetrischen Gassensors zur Inline-Überwachung der H2O2-Konzentration in aseptischen Abfüllsystemen
T2  - Tagungsband: Sensoren und Messsysteme 2010
N2  - In aseptischen Abfüllsystemen wird Wasserstoffperoxid in der Gasphase aufgrund der stark oxidativen Wirkung zur Packstoffentkeimung eingesetzt. Dabei wird die Effizienz der Entkeimung im Wesentlichen von der vorliegenden H2O2-Konzentration im Packstoff bestimmt. Zur Inline-Überwachung der H2O2-Konzentration wurde ein kalorimetrischer Gassensor auf Basis einer flexiblen Polyimidfolie aus temperatursensitiven Dünnschicht-Widerständen und Mangan(IV)-oxid als katalytische Transducerschicht realisiert. Der Sensor weist ein lineares Ansprechverhalten mit einer Sensitivität von 7,15 °C/Vol.-% in einem H2O2-Konzentrationsbereich von 0 bis 8 Vol.-% auf. Weiterhin wurde zur Auslesung des Sensorsignals eine RFID-Elektronik, bestehend aus einem Sensor-Tag und einer Sende-/Empfangseinheit ausgelegt, sowie eine Abfolge des Messzyklus aufgestellt. Im weiteren Verlauf soll der kalorimetrische Gassensor mit der RFID-Elektronik gekoppelt und in eine Testverpackung zur Inline-Überwachung der H2O2-Konzentration in aseptischen Abfüllsystemen implementiert werden.
Y1  - 2010
SN  - 978-3-8007-3260-9
N1  - Sensoren und Messsysteme 2010 - 15. ITG/GMA-Fachtagung, 18.05.2010 - 19.05.2010 in Nürnberg
SP  - 607
EP  - 612
PB  - VDE Verlag
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Werner, Frederik
A1  - Spelthahn, Heiko
A1  - Schöning, Michael Josef
A1  - Krumbe, Christoph
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Keusgen, Michael
T1  - Neue Ansteuerungselektronik für LAPS-basierte Biosensoren zur gleichzeitig ortsaufgelösten Messung der pH-Konzentration
T2  - Tagungsband: Sensoren und Messsysteme 2010
N2  - Ein lichtadressierbarer potentiometrischer Sensor (LAPS) kann die Konzentration eines oder mehrerer Analyten ortsaufgelöst auf der Sensoroberfläche nachweisen. Dazu wird mit einer modulierten Lichtquelle die Halbleiterstruktur des zu untersuchenden Bereiches angeregt und ein entsprechender Photostrom ausgelesen. Durch gleichzeitige Anregung mehrere Bereiche durch Lichtquellen mit unterschiedlichen Modulationsfrequenzen können diese auch zeitgleich ausgelesen werden. Mit der neuen, hier vorgestellten Ansteuerungselektronik integriert in einem "Field Programmable Gate Array" (FPGA) ist es möglich, mehrere Leuchtquellen gleichzeitig mit unterschiedlichen, während der Laufzeit festlegbaren Frequenzen, Phasen und Lichtintensitäten zu betreiben. Somit kann das Frequenzverhalten des Sensors untersucht und die Konzentration des Analyten über das Oberflächenpotential mit Hilfe von Strom/Spannungs-Kurven und Phase/Spannungs-Kurven bestimmt werden.
Y1  - 2010
SN  - 978-3-8007-3260-9
N1  - Sensoren und Messsysteme 2010 - 15. ITG/GMA-Fachtagung, 18.05.2010 - 19.05.2010 in Nürnberg
SP  - 109
EP  - 114
PB  - VDE Verlag
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Wagner, Holger
A1  - Schöning, Michael Josef
T1  - Automatisiertes „wafer level“-Testsystem zur Charakterisierung von siliziumbasierten Chemo- und Biosensoren
T2  - Tagungsband: Sensoren und Messsysteme 2010
N2  - Es wurde ein automatisiertes, computerunterstütztes Testsystem für die Funktionsprüfung und Charakterisierung von (bio-)chemischen Sensoren auf Waferebene entwickelt und in einen konventionellen Spitzenmessplatz integriert. Das System ermöglicht die Charakterisierung und Identifizierung „funktionstauglicher“ Sensoren bereits auf Waferebene zwischen den einzelnen Herstellungsschritten, wodurch weitere, bisher übliche Verarbeitungsschritte wie das Fixieren, Bonden und Verkapseln für die defekten oder nicht funktionstauglichen Sensorstrukturen entfällt. Außerdem bietet eine speziell entworfene miniaturisierte Durchflussmesszelle die Möglichkeit, bereits auf Waferlevel die Sensitivität, Drift, Hysterese und Ansprechzeit der (bio-)chemischen Sensoren zu charakterisieren. Das System wurde exemplarisch mit kapazitiven, pH-sensitiven EIS- (Elektrolyt-Isolator-Silizium) Strukturen und ISFET- (ionensensitiver Feldeffekttransistor) Strukturen mit verschiedenen Geometrien und Gate-Layouts getestet.
Y1  - 2010
SN  - 978-3-8007-3260-9
N1  - Sensoren und Messsysteme 2010 - 15. ITG/GMA-Fachtagung, 18.05.2010 - 19.05.2010 in Nürnberg
SP  - 89
EP  - 92
PB  - VDE Verlag
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Ribitsch, Doris
A1  - Heumann, Sonja
A1  - Karl, Wolfgang
A1  - Gerlach, Jochen
A1  - Leber, Regina
A1  - Birner-Gruenberger, Ruth
A1  - Gruber, Karl
A1  - Eiteljoerg, Inge
A1  - Remler, Peter
A1  - Siegert, Petra
A1  - Lange, Jennifer
A1  - Maurer, Karl-Heinz
A1  - Berg, Gabriele
A1  - Guebitz, G. M.
A1  - Schwab, H.
T1  - Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli
JF  - Journal of biotechnology
N2  - A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3.

From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2.
KW  - Alginate beads
KW  - Stenotrophomonas maltophilia
KW  - Detergent protease
Y1  - 2012
U6  - https://doi.org/10.1016/j.jbiotec.2011.09.025
SN  - 1873-4863 (E-Journal); 0168-1656 (Print)
VL  - 157
IS  - 1
SP  - 140
EP  - 147
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kirchner, Patrick
A1  - Oberländer, Jan
A1  - Friedrich, Peter
A1  - Rysstad, Gunnar
A1  - Berger, Jörg
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry
JF  - Procedia Engineering
N2  - A calorimetric gas sensor is presented for the monitoring of gas-phase H2O2 at elevated temperature during sterilization processes in aseptic food industry. The sensor consists of two temperature-sensitive thin-film resistances built up on a polyimide foil with a thickness of 25 μm, which are passivated with a layer of SU-8 photo resist and catalytically activated with manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilizes the elevated temperature of an evaporated H2O2 aerosol. In an experimental set-up, the sensor has shown a sensitivity of 4.78 °C/(%v/v) in a H2O2 concentration range of 0 to 10% v/v at an evaporation temperature of 240 ∘C. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied evaporation temperatures of the gas stream. The sensor characterization demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of sterilization processes.
Y1  - 2010
U6  - https://doi.org/10.1016/j.proeng.2010.09.098
SN  - 1877-7058
N1  - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria
VL  - 5
SP  - 264
EP  - 267
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Miyamoto, Ko-ichiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Novel combination of digital light processing (DLP) and light-addressable potentiometric sensors (LAPS) for flexible chemical imaging
JF  - Procedia Engineering
N2  - Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach of read out in a light-addressable potentiometric sensor (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device which allows fast and flexible generation of light patterns. With the help of these light patterns the sensor surface of the LAPS device can be read out sequentially in a raster like scheme (scanning LAPS). The DLP approach has several advantages compared to conventional scanning LAPS set-ups, e.g., the spot size, the shape and the intensity of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of measurement.
Y1  - 2010
U6  - https://doi.org/10.1016/j.proeng.2010.09.161
SN  - 1877-7058
N1  - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria
VL  - 5
SP  - 520
EP  - 523
PB  - Elsevier
CY  - Amsterdam
ER  -