TY  - JOUR
A1  - Spelthahn, Heiko
A1  - Kirsanov, Dmitry
A1  - Legin, Andrey
A1  - Osterrath, Thomas
A1  - Schubert, Jürgen
A1  - Zander, Willi
A1  - Schöning, Michael Josef
T1  - Development of a thin-film sensor array for analytical monitoring of heavy metals in aqueous solutions
JF  - Physica Status Solidi (a)
N2  - In industrial processes there is a variety of heavy metals (e.g., copper, zinc, cadmium, and lead) in use for wires, coatings, paints, alloys, batteries, etc. Since the application of these transition metals for industry is inevitable, it is a vital task to develop proper analytical techniques for their monitoring at low activity levels, especially because most of these elements are acutely toxic for biological organisms. The determination of ions in solution by means of a simple and inexpensive sensor array is, therefore, a promising task. In this work, a sensor array with heavy metal-sensitive chalcogenide glass membranes for the simultaneous detection of the four ions Ag⁺, Cu2⁺, Cd2⁺, and Pb2⁺ in solution is realized. The results of the physical characterization by means of microscopy, profilometry, Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM) as well as the electrochemical characterization by means of potentiometric measurements are presented. Additionally, the possibility to expand the sensor array by polymeric sensor membranes is discussed.
Y1  - 2012
SN  - 1862-6319
U6  - http://dx.doi.org/10.1002/pssa.201100733
VL  - 209
IS  - 5
SP  - 885
EP  - 891
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wert, Stefan
A1  - Iken, Heiko
A1  - Schöning, Michael Josef
A1  - Matysik, Frank-Michael
T1  - Development of a temperature‐pulse enhanced electrochemical glucose biosensor and characterization of its stability via scanning electrochemical microscopy
JF  - Electroanalysis
N2  - Glucose oxidase (GOx) is an enzyme frequently used in glucose biosensors. As increased temperatures can enhance the performance of electrochemical sensors, we investigated the impact of temperature pulses on GOx that was drop-coated on flattened Pt microwires. The wires were heated by an alternating current. The sensitivity towards glucose and the temperature stability of GOx was investigated by amperometry. An up to 22-fold increase of sensitivity was observed. Spatially resolved enzyme activity changes were investigated via scanning electrochemical microscopy. The application of short (<100 ms) heat pulses was associated with less thermal inactivation of the immobilized GOx than long-term heating.
Y1  - 2021
U6  - http://dx.doi.org/10.1002/elan.202100089
SN  - 1521-4109
IS  - Early View
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Jildeh, Zaid B.
A1  - Kirchner, Patrick
A1  - Oberländer, Jan
A1  - Vahidpour, Farnoosh
A1  - Wagner, Patrick H.
A1  - Schöning, Michael Josef
T1  - Development of a package-sterilization process for aseptic filling machines: A numerical approach and validation for surface treatment with hydrogen peroxide
JF  - Sensor and Actuators A: Physical
N2  - Within the present work a sterilization process by a heated gas mixture that contains hydrogen peroxide (H₂O₂) is validated by experiments and numerical modeling techniques. The operational parameters that affect the sterilization efficacy are described alongside the two modes of sterilization: gaseous and condensed H₂O₂. Measurements with a previously developed H₂O₂ gas sensor are carried out to validate the applied H₂O₂ gas concentration during sterilization. We performed microbiological tests at different H₂O₂ gas concentrations by applying an end-point method to carrier strips, which contain different inoculation loads of Geobacillus stearothermophilus spores. The analysis of the sterilization process of a pharmaceutical glass vial is performed by numerical modeling. The numerical model combines heat- and advection-diffusion mass transfer with vapor–pressure equations to predict the location of condensate formation and the concentration of H₂O₂ at the packaging surfaces by changing the gas temperature. For a sterilization process of 0.7 s, a H₂O₂ gas concentration above 4% v/v is required to reach a log-count reduction above six. The numerical results showed the location of H₂O₂ condensate formation, which decreases with increasing sterilant-gas temperature. The model can be transferred to different gas nozzle- and packaging geometries to assure the absence of H₂O₂ residues.
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.sna.2019.111691
SN  - 0924-4247
VL  - 303
IS  - 111691
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Iken, Heiko
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development of a multi‐parameter sensor chip for the simultaneous detection of organic compounds in biogas processes
JF  - Physica status solidi (a)
N2  - An enzyme-based multi-parameter biosensor is developed for monitoring the concentration of formate, d-lactate, and l-lactate in biological samples. The sensor is based on the specific dehydrogenation by an oxidized β-nicotinamide adenine dinucleotide (NAD+)-dependent dehydrogenase (formate dehydrogenase, d-lactic dehydrogenase, and l-lactic dehydrogenase, respectively) in combination with a diaphorase from Clostridium kluyveri (EC 1.8.1.4). The enzymes are immobilized on a platinum working electrode by cross-linking with glutaraldehyde (GA). The principle of the determination scheme in case of l-lactate is as follows: l-lactic dehydrogenase (l-LDH) converts l-lactate into pyruvate by reaction with NAD+. In the presence of hexacyanoferrate(III), the resulting reduced β-nicotinamide adenine dinucleotide (NADH) is then regenerated enzymatically by diaphorase. The electrochemical detection is based on the current generated by oxidation of hexacyanoferrate(II) at an applied potential of +0.3 V vs. an Ag/AgCl reference electrode. The biosensor will be electrochemically characterized in terms of linear working range and sensitivity. Additionally, the successful practical application of the sensor is demonstrated in an extract from maize silage.
Y1  - 2015
U6  - http://dx.doi.org/10.1002/pssa.201431894
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1306
EP  - 1312
PB  - Wiley
CY  - Weinheim
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). 207 (2010), H. 4
Y1  - 2010
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
SP  - 913
EP  - 918
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
A1  - Wang, C.
A1  - Otto, R.
A1  - Yoshinobu, T.
T1  - Development of a handheld 16 channel pen-type LAPS for electrochemical sensing
JF  - Sensors and Actuators B. 108 (2005)
Y1  - 2005
SN  - 0925-4005
SP  - 808
EP  - 814
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
A1  - Wang, C.
A1  - Otto, R.
A1  - Yoshinobu, T.
T1  - Development of a handheld 16 channel pen-type LAPS for electrochemical sensing
JF  - Technical digest of the 10th International Meeting on Chemical Sensors, July 11 - 14, 2004, Tsukuba, Japan / Japan Association of Chemical Sensors
Y1  - 2004
N1  - Chemical sensors ; 20.2004 Suppl. B. IMCS ; (10, 2004, Tsukuba) ; International Meeting on Chemical Sensors ; (10 : ; 2004.07.11-14 : ; Tsukuba)
SP  - 136
EP  - 137
PB  - Japan Association of Chemical Sensors
CY  - Fukuoka
ER  - 
TY  - JOUR
A1  - Iken, Heiko
A1  - Bronder, Thomas
A1  - Goretzki, Alexander
A1  - Kriesel, Jana
A1  - Ahlborn, Kristina
A1  - Gerlach, Frank
A1  - Vonau, Winfried
A1  - Zander, Willi
A1  - Schubert, Jürgen
A1  - Schöning, Michael Josef
T1  - Development of a Combined pH- and Redox-Sensitive Bi-Electrode Glass Thin-Film Sensor
JF  - physica status solidi a : applications and materials sciences
Y1  - 2019
U6  - http://dx.doi.org/10.1002/pssa.201900114
SN  - 1862-6319
VL  - 216
IS  - 12
SP  - 1
EP  - 8
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Keusgen, M.
A1  - Jünger, M.
A1  - Krest, I.
A1  - Schöning, Michael Josef
T1  - Development of a biosensor specific for cysteine sulfoxides
JF  - Biosensors & Bioelectronics. 18 (2003), H. 5-6
Y1  - 2003
SN  - 0956-5663
SP  - 805
EP  - 812
ER  - 
TY  - JOUR
A1  - Turek, Monika
A1  - Ketterer, Lothar
A1  - Claßen, Melanie
A1  - Berndt, Heinz
A1  - Elbers, Gereon
A1  - Krüger, Peter
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development and Electrochemical Investigations of an EIS-(Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection
JF  - Sensors
Y1  - 2007
SN  - 1424-8220
VL  - 7
IS  - 8
SP  - 1415
EP  - 1426
ER  - 
TY  - JOUR
A1  - Molinnus, Denise
A1  - Muschallik, Lukas
A1  - Gonzalez, Laura Osorio
A1  - Bongaerts, Johannes
A1  - Wagner, Torsten
A1  - Selmer, Thorsten
A1  - Siegert, Petra
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development and characterization of a field-effect biosensor for the detection of acetoin
JF  - Biosensors and Bioelectronics
N2  - A capacitive electrolyte-insulator-semiconductor (EIS) field-effect biosensor for acetoin detection has been presented for the first time. The EIS sensor consists of a layer structure of Al/p-Si/SiO₂/Ta₂O₅/enzyme acetoin reductase. The enzyme, also referred to as butane-2,3-diol dehydrogenase from B. clausii DSM 8716T, has been recently characterized. The enzyme catalyzes the (R)-specific reduction of racemic acetoin to (R,R)- and meso-butane-2,3-diol, respectively. Two different enzyme immobilization strategies (cross-linking by using glutaraldehyde and adsorption) have been studied. Typical biosensor parameters such as optimal pH working range, sensitivity, hysteresis, linear concentration range and long-term stability have been examined by means of constant-capacitance (ConCap) mode measurements. Furthermore, preliminary experiments have been successfully carried out for the detection of acetoin in diluted white wine samples.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.bios.2018.05.023
VL  - 115
SP  - 1
EP  - 6
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Werner, Frederik
A1  - Miyamoto, Ko-Ichiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Development and characterisation of a compact light-addressable potentiometric sensor (LAPS) based on the digital light processing (DLP) technology for flexible chemical imaging
JF  - Sensors and Actuators B: Chemical
N2  - Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (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 addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape 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 the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2010.12.003
SN  - 0925-4005
N1  - Part of special issue "Eurosensors XXIV, 2010"
VL  - 170
SP  - 34
EP  - 39
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Sousa, Marcos A. M.
A1  - Siqueira, Jose R. Jr.
A1  - Vercik, Andres
A1  - Schöning, Michael Josef
A1  - Oliveira, Osvaldo N. Jr.
T1  - Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors
JF  - IEEE Sensors Journal
N2  - The capacitive electrolyte–insulator–semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte–insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors.
Y1  - 2017
U6  - http://dx.doi.org/10.1109/JSEN.2017.2653238
SN  - 1558-1748
VL  - 17
IS  - 6
SP  - 1735
EP  - 1740
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Takenaga, Shoko
A1  - Wagner, Patrick
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli K12 with a multi-​chamber-​based LAPS system
JF  - Physica status solidi (a)
N2  - On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable “down times” during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements.
Y1  - 2016
U6  - http://dx.doi.org/10.1002/pssa.201533043
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1479
EP  - 1485
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Krumbe, Christoph
A1  - Schumacher, Katharina
A1  - Groebel, Simone
A1  - Spelthahn, Heiko
A1  - Stellberg, Michael
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli by a light-addressable potentiometric sensor
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1340
EP  - 1344
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
T1  - Determination of cadmium concentration and pH value in aqueous solutions by means of a handheld light-addressable potentiometric sensor (LAPS) device
JF  - Electrochemical sensor analysis / edited by S. Alegret ...
Y1  - 2007
SN  - 978-0-444-53133-9
N1  - Wilson & Wilson's comprehensive analytical chemistry ; 49
SP  - e35
EP  - e44
PB  - Elsevier
CY  - Amsterdam
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  - http://dx.doi.org/10.1002/pssa.201431882
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1289
EP  - 1298
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Bohrn, Ulrich
A1  - Mucha, Andreas
A1  - Werner, Frederik
A1  - Stütz, Evamaria
A1  - Bäcker, Matthias
A1  - Krumbe, Christoph
A1  - Schienle, Meinrad
A1  - Fleischer, Maximilian
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Detection of toxic chromium species in water using cellbased sensor systems
Y1  - 2012
SN  - 978-3-9813484-2-2
U6  - http://dx.doi.org/10.5162/IMCS2012/P2.1.14
SP  - 1364
EP  - 1367
ER  - 
TY  - CHAP
A1  - Takenaga, Shoko
A1  - Herrera, Cony F.
A1  - Werner, Frederik
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Schöning, Michael Josef
A1  - Öhlschläger, Peter
A1  - Wagner, Torsten
T1  - Detection of the metabolic activity of cells by differential measurements based on a single light-addressable potentiometric sensor chip
T2  - 11. Dresdner Sensor-Symposium : 9.-11.12.2013
Y1  - 2013
SN  - 978-3-9813484-5-3
SP  - 63
EP  - 67
ER  - 
TY  - JOUR
A1  - Jablonski, Melanie
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Detection of plant virus particles with a capacitive field-effect sensor
JF  - Analytical and Bioanalytical Chemistry
N2  - Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.
KW  - Plant virus
KW  - Capacitive field-effect sensor
KW  - Tobacco mosaic virus (TMV)
KW  - Label-free detection
KW  - Zeta potential
Y1  - 2021
U6  - http://dx.doi.org/10.1007/s00216-021-03448-8
SN  - 1618-2650
N1  - Corresponding authors: Arshak Poghossian & Michael J. Schöning
VL  - 413
SP  - 5669
EP  - 5678
PB  - Springer Nature
CY  - Cham
ER  -