TY  - JOUR
A1  - Reisert, Steffen
A1  - Geissler, H.
A1  - Weiler, C.
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Multiple sensor-type system for monitoring the microbicidal effectiveness of aseptic sterilisation processes
JF  - Food control
N2  - The present work describes a novel multiple sensor-type system for the real-time analysis of aseptic sterilisation processes employing gaseous hydrogen peroxide (H2O2) as a sterilant. The inactivation kinetics of Bacillus atrophaeus by gaseous H2O2 have been investigated by means of a methodical calibration experiment, taking into account the process variables H2O2 concentration, humidity and gas temperature. It has been found that the microbicidal effectiveness at H2O2 concentrations above 2% v/v is largely determined by the concentration itself, while at lower H2O2 concentrations, the gas temperature and humidity play a leading role. Furthermore, the responses of different types of gas sensors towards the influencing factors of the sterilisation process have been analysed within the same experiment. Based on a correlation established between the inactivation kinetics and the sensor responses, a calorimetric H2O2 sensor and a metal-oxide semiconductor (MOX) sensor have been identified as possible candidates for monitoring the microbicidal effectiveness of aseptic sterilisation processes employing gaseous H2O2. Therefore, two linear models that describe the relationship between sensor response and microbicidal effectiveness have been proposed.
Y1  - 2015
U6  - https://doi.org/10.1016/j.foodcont.2014.07.063
SN  - 1873-7129 (E-Journal); 0956-7135 (Print)
VL  - 47
SP  - 615
EP  - 622
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Krischer, M.
A1  - Leinhos, Marcel
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - An application of field-effect sensors for in-situ monitoring of degradation of biopolymers
JF  - Sensors and actuators B: Chemical
N2  - The characterization of the degradation kinetics of biodegradable polymers is mandatory with regard to their proper application. In the present work, polymer-modified electrolyte–insulator–semiconductor (PMEIS) field-effect sensors have been applied for in-situ monitoring of the pH-dependent degradation kinetics of the commercially available biopolymer poly(d,l-lactic acid) (PDLLA) in buffer solutions from pH 3 to pH 13. PDLLA films of 500 nm thickness were deposited on the surface of an Al–p-Si–SiO2–Ta2O5 structure from a polymer solution by means of spin-coating method. The PMEIS sensor is, in principle, capable to detect any changes in bulk, surface and interface properties of the polymer induced by degradation processes. A faster degradation has been observed for PDLLA films exposed to alkaline solutions (pH 9, pH 11 and pH 13).
Y1  - 2015
U6  - https://doi.org/10.1016/j.snb.2014.10.058
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
VL  - 207, Part B
SP  - 954
EP  - 959
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Recent developments of chemical imaging sensor systems based on the principle of the light-addressable potentiometric sensor
JF  - Sensors and actuators B: Chemical
N2  - The light-addressable potentiometric sensor (LAPS) is an electrochemical sensor with a field-effect structure to detect the variation of the Nernst potential at its sensor surface, the measured area on which is defined by illumination. Thanks to this light-addressability, the LAPS can be applied to chemical imaging sensor systems, which can visualize the two-dimensional distribution of a particular target ion on the sensor surface. Chemical imaging sensor systems are expected to be useful for analysis of reaction and diffusion in various electrochemical and biological samples. Recent developments of LAPS-based chemical imaging sensor systems, in terms of the spatial resolution, measurement speed, image quality, miniaturization and integration with microfluidic devices, are summarized and discussed.
Y1  - 2015
U6  - https://doi.org/10.1016/j.snb.2014.09.002
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
VL  - 207, Part B
SP  - 926
EP  - 932
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Yeap, W. S.
A1  - Martens, D.
A1  - Liu, X.
A1  - Bienstman, P.
A1  - Fahlman, M.
A1  - Schöning, Michael Josef
A1  - Michiels, L.
A1  - Haenen, K.
A1  - Serpengüzel, A.
A1  - Wagner, Patrick
T1  - Photonic studies on polymer-coated sapphire-spheres : a model system for biological ligands
JF  - Sensors and actuators A: Physical
N2  - In this study we show an optical biosensor concept, based on elastic light scattering from sapphire microspheres. Transmitted and elastic scattering intensity of the microspheres (radius 500 μm, refractive index 1.77) on an optical fiber half coupler is analyzed at 1510 nm. The 0.43 nm angular mode spacing of the resonances is comparable to the angular mode spacing value estimated using the optical size of the microsphere. The spectral linewidths of the resonances are in the order of 0.01 nm, which corresponds to quality factors of approximately 105. A polydopamine layer is used as a functionalizing agent on sapphire microspherical resonators in view of biosensor implementation. The varying layer thickness on the microsphere is determined as a function of the resonance wavelength shift. It is shown that polymer functionalization has a minor effect on the quality factor. This is a promising step toward the development of an optical biosensor.
Y1  - 2015
U6  - https://doi.org/10.1016/j.sna.2014.11.024
SN  - 1873-3069 (E-Journal); 0924-4247 (Print)
VL  - 222
SP  - 212
EP  - 219
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Mayer, Dirk
A1  - Schöning, Michael Josef
T1  - Gating capacitive field-effect sensors by the charge of nanoparticle/molecule hybrids
JF  - Nanoscale
Y1  - 2015
U6  - https://doi.org/10.1039/C4NR05987E
SN  - 2040-3372 (E-Journal); 2040-3364 (Print)
SP  - 1023
EP  - 1031
PB  - Royal Society of Chemistry (RSC)
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Warmer, Johannes
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
A1  - Kaul, Peter
T1  - Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors
JF  - Physica status solidi (a)
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431882
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1289
EP  - 1298
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Delle, Lotta E.
A1  - Huck, Christina
A1  - Bäcker, Matthias
A1  - Müller, Frank
A1  - Grandthyll, Samuel
A1  - Jacobs, Karin
A1  - Lilischkis, Rainer
A1  - Vu, Xuan T.
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
A1  - Thoelen, Roland
A1  - Weil, Maryam
A1  - Ingebrandt, Sven
T1  - Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide
JF  - Physica status solidi (a)
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431863
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1327
EP  - 1334
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Takenaga, Shoko
A1  - Schneider, Benno
A1  - Erbay, E.
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Fabrication of biocompatible lab-on-chip devices for biomedical applications by means of a 3D-printing process
JF  - Physica status solidi (a)
N2  - A new microfluidic assembly method for semiconductor-based biosensors using 3D-printing technologies was proposed for a rapid and cost-efficient design of new sensor systems. The microfluidic unit is designed and printed by a 3D-printer in just a few hours and assembled on a light-addressable potentiometric sensor (LAPS) chip using a photo resin. The cell growth curves obtained from culturing cells within microfluidics-based LAPS systems were compared with cell growth curves in cell culture flasks to examine biocompatibility of the 3D-printed chips. Furthermore, an optimal cell culturing within microfluidics-based LAPS chips was achieved by adjusting the fetal calf serum concentrations of the cell culture medium, an important factor for the cell proliferation.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201532053
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1347
EP  - 1352
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Molinnus, Denise
A1  - Bäcker, Matthias
A1  - Iken, Heiko
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Concept for a biomolecular logic chip with an integrated sensor and actuator function
JF  - Physica status solidi (a)
N2  - A concept for a new generation of an integrated multi-functional biosensor/actuator system is developed, which is based on biomolecular logic principles. Such a system is expected to be able to detect multiple biochemical input signals simultaneously and in real-time and convert them into electrical output signals with logical operations such as OR, AND, etc. The system can be designed as a closed-loop drug release device triggered by an enzyme logic gate, while the release of the drug induced by the actuator at the required dosage and timing will be controlled by an additional drug sensor. Thus, the system could help to make an accurate and specific diagnosis. The presented concept is exemplarily demonstrated by using an enzyme logic gate based on a glucose/glucose oxidase system, a temperature-responsive hydrogel mimicking the actuator function and an insulin (drug) sensor. In this work, the results of functional testing of individual amperometric glucose and insulin sensors as well as an impedimetric sensor for the detection of the hydrogel swelling/shrinking are presented.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431913
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1382
EP  - 1388
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Oberländer, Jan
A1  - Kirchner, Patrick
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Strategies in developing thin-film sensors for monitoring aseptic food processes : Theoretical considerations and investigations of passivation materials
JF  - Electrochimica Acta
N2  - The sterilization of packages in aseptic food processes is highly significant to maintain a consumer-safe product with extended shelf-life. Today, the sterilization of food packages is predominantly accomplished by gaseous hydrogen peroxide (H2O2) in combination with heat. In order to monitor this sterilization process, calorimetric gas sensors as differential set-up of two platinum temperature sensors representing a catalytically active (additionally deposition of MnO2) and a passive segment have been recently developed. The temperature rise of the exothermic decomposition serves as an indicator of the present H2O2 concentration. In the present work, a theoretical approach considering the sensor’s thermochemistry and physical transport phenomena was formulated to evaluate the temperature rise based on the energy content of gaseous H2O2. In a further part of this work, three polymers have been analyzed with respect to their application as passivation materials. The examined polymers are photoresist SU-8, perfluoroalkoxy (PFA) and fluorinated ethylene propylene (FEP). Thermal analyses by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have been conducted to determine the operation limits of the polymers. The overall chemical resistance and stability of the polymers against the harsh environmental conditions during the sterilization process have been examined by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).
Y1  - 2015
U6  - https://doi.org/10.1016/j.electacta.2015.06.126
SN  - 0013-4686
VL  - 183
SP  - 130
EP  - 136
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Schusser, Sebastian
A1  - Bäcker, M.
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  - Breuer, Lars
A1  - Raue, Markus
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, Ronald
A1  - Wagner, Torsten
T1  - Light-stimulated hydrogel actuators with incorporated graphene oxide for microfluidic applications
T2  - 12. Dresdner Sensor-Symposium 2015
Y1  - 2015
U6  - https://doi.org/10.5162/12dss2015/P5.8
SP  - 206
EP  - 209
ER  - 
TY  - CHAP
A1  - Oberländer, Jan
A1  - Jildeh, Zaid B.
A1  - Kirchner, Patrick
A1  - Wendeler, Luisa
A1  - Bromm, Alexander
A1  - Iken, Heiko
A1  - Wagner, Patrick
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Experimental and numerical evaluation of interdigitated electrode array for monitoring gaseous sterilization processes
T2  - 12. Dresdner Sensor-Symposium 2015
Y1  - 2015
U6  - https://doi.org/10.5162/12dss2015/P3.11
SP  - 163
EP  - 168
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Krischer, Maximillian
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Monitoring of the Enzymatically Catalyzed Degradation of Biodegradable Polymers by Means of Capacitive Field-Effect Sensors
JF  - Analytical Chemistry
N2  - Designing novel or optimizing existing biodegradable polymers for biomedical applications requires numerous tests on the effect of substances on the degradation process. In the present work, polymer-modified electrolyte–insulator–semiconductor (PMEIS) sensors have been applied for monitoring an enzymatically catalyzed degradation of polymers for the first time. The thin films of biodegradable polymer poly(d,l-lactic acid) and enzyme lipase were used as a model system. During degradation, the sensors were read-out by means of impedance spectroscopy. In order to interpret the data obtained from impedance measurements, an electrical equivalent circuit model was developed. In addition, morphological investigations of the polymer surface have been performed by means of in situ atomic force microscopy. The sensor signal change, which reflects the progress of degradation, indicates an accelerated degradation in the presence of the enzyme compared to hydrolysis in neutral pH buffer media. The degradation rate increases with increasing enzyme concentration. The obtained results demonstrate the potential of PMEIS sensors as a very promising tool for in situ and real-time monitoring of degradation of polymers.
Y1  - 2015
U6  - https://doi.org/10.1021/acs.analchem.5b00617
SN  - 1520-6882
VL  - 87
IS  - 13
SP  - 6607
EP  - 6613
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Miyamato, Ko-ichiro
A1  - Sakakita, Sakura
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Application of chemical imaging sensor to in-situ pH imaging in the vicinity of a corroding metal surface
JF  - Electrochimica Acta
N2  - The chemical imaging sensor was applied to in-situ pH imaging of the solution in the vicinity of a corroding surface of stainless steel under potentiostatic polarization. A test piece of polished stainless steel was placed on the sensing surface leaving a narrow gap filled with artificial seawater and the stainless steel was corroded under polarization. The pH images obtained during polarization showed correspondence between the region of lower pH and the site of corrosion. It was also found that the pH value in the gap became as low as 2 by polarization, which triggered corrosion.
Y1  - 2015
U6  - https://doi.org/10.1016/j.electacta.2015.07.184
SN  - 0013-4686
VL  - 183
SP  - 137
EP  - 142
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Schöning, Michael Josef
T1  - Label-free sensing of biomolecules by their intrinsic molecular charge using field-effect devices
T2  - Semiconductor Micro- and Nanoelectonics : Proceedings of the tenth international conference, Yerevan, Armenia, September 11-13
Y1  - 2015
SN  - 978-5-8084-1991-9
SP  - 61
EP  - 63
ER  - 
TY  - THES
A1  - Schusser, Sebastian
T1  - Sensor-based degradation monitoring for the evaluation of (bio)degradable polymers
Y1  - 2015
N1  - Universiteit Hasselt, FH Aachen, Dissertation, 2015;

Printausgabe in der Bibliothek vorhanden: 61 UWJ 5
PB  - Universiteit Hasselt ; FH Aachen
CY  - Hasselt ; Aachen
ER  - 
TY  - JOUR
A1  - Arreola, Julio
A1  - Mätzkow, Malte
A1  - Durán, Marlena Palomar
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of the immobilization of bacterial spores on glass substrates with organosilanes
JF  - Physica status solidi (A) : Applications and materials science
N2  - Spores can be immobilized on biosensors to function as sensitive recognition elements. However, the immobilization can affect the sensitivity and reproducibility of the sensor signal. In this work, three different immobilization strategies with organosilanes were optimized and characterized to immobilize Bacillus atrophaeus spores on glass substrates. Five different silanization parameters were investigated: nature of the solvent, concentration of the silane, silanization time, curing process, and silanization temperature. The resulting silane layers were resistant to a buffer solution (e.g., Ringer solution) with a polysorbate (e.g., Tween®80) and sonication.
KW  - silanization
KW  - organosilanes
KW  - immobilization
KW  - endospores
KW  - biosensors
KW  - Bacillus atrophaeus
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201532914
SN  - 1862-6319
VL  - 213
IS  - 6
SP  - 1463
EP  - 1470
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Schöning, Michael Josef
T1  - Sensing of double-stranded DNA molecules by their intrinsic molecular charge using the light-addressable potentiometric sensor
JF  - Sensors and Actuators B: Chemical
N2  - A multi-spot light-addressable potentiometric sensor (LAPS), which belongs to the family of semiconductor field-effect devices, was applied for label-free detection of double-stranded deoxyribonucleic acid (dsDNA) molecules by their intrinsic molecular charge. To reduce the distance between the DNA charge and sensor surface and thus, to enhance the electrostatic coupling between the dsDNA molecules and the LAPS, the negatively charged dsDNA molecules were electrostatically adsorbed onto the gate surface of the LAPS covered with a positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)). The surface potential changes in each spot of the LAPS, induced by the layer-by-layer adsorption of a PAH/dsDNA bilayer, were recorded by means of photocurrent-voltage and constant-photocurrent measurements. In addition, the surface morphology of the gate surface before and after consecutive electrostatic adsorption of PAH and dsDNA layers was studied by atomic force microscopy measurements. Moreover, fluorescence microscopy was used to verify the successful adsorption of dsDNA molecules onto the PAH-modified LAPS surface. A high sensor signal of 25 mV was registered after adsorption of 10 nM dsDNA molecules. The lower detection limit is down to 0.1 nM dsDNA. The obtained results demonstrate that the PAH-modified LAPS device provides a convenient and rapid platform for the direct label-free electrical detection of in-solution hybridized dsDNA molecules.
KW  - Layer-by-layer adsorption
KW  - Poly(allylamine hydrochloride)
KW  - Label-free detection
KW  - DNA biosensor
KW  - LAPS
KW  - Field effect
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.02.004
SN  - 0925-4005
IS  - 229
SP  - 506
EP  - 512
PB  - Elsevier
CY  - Amsterdam
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, M.
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  -