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  - http://dx.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  - Bohrn, U.
A1  - Stütz, E.
A1  - Fuchs, K.
A1  - Fleischer, M.
A1  - Schöning, Michael Josef
A1  - Wagner, P.
T1  - Monitoring of irritant gas using a whole-cell-based sensor system
JF  - Sensors and Actuators B: Chemical
N2  - Cell-based sensors for the detection of gases have long been underrepresented, due to the cellular requirement of being cultured in a liquid environment. In this work we established a cell-based gas biosensor for the detection of toxic substances in air, by adapting a commercial sensor chip (Bionas®), previously used for the measurement of pollutants in liquids. Cells of the respiratory tract (A549, RPMI 2650, V79), which survive at a gas phase in a natural context, are used as biological receptors. The physiological cell parameters acidification, respiration and morphology are continuously monitored in parallel. Ammonia was used as a highly water-soluble model gas to test the feasibility of the sensor system. Infrared measurements confirmed the sufficiency of the medium draining method. This sensor system provides a basis for many sensor applications such as environmental monitoring, building technology and public security.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2012.05.088
SN  - 0925-4005
VL  - 175
SP  - 208
EP  - 217
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Gasparyan, F.V.
A1  - Vitusevich, S.A.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Modified charge fluctuation noise model for electrolyte-insulator-semiconductor devices
JF  - Modern Physics Letters B (MPLB). 25 (2011), H. 11
Y1  - 2011
SN  - 0217-9849
SP  - 831
EP  - 840
PB  - World Scientific Publ.
CY  - Singapur
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Buß, G.
A1  - Lüth, H.
A1  - Schultze, J.W.
T1  - Modifications and characterization of a silicon-based microelectrode array
JF  - Electrochimica Acta. 44 (1999), H. 21-22
Y1  - 1999
SN  - 0013-4686
SP  - 3899
EP  - 3910
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Näther, Niko
A1  - Auger, V.
A1  - Poghossian, Arshak
A1  - Koudelka-Hep, M.
T1  - Miniaturized flow-through cell with integrated capacitive EIS sensors fabricated at wafer level using Si and Su-8 technologies
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  - 554
EP  - 555
PB  - Japan Association of Chemical Sensors
CY  - Fukuoka
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Kaneko, Kazumi
A1  - Matsuo, Akira
A1  - Wagner, Torsten
A1  - Kanoh, Shin`ichiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Miniaturized chemical imaging sensor system using an OLED display panel
JF  - Procedia Engineering. 5 (2010)
Y1  - 2010
SN  - 1877-7058
N1  - Eurosensor XXIV Conference
SP  - 516
EP  - 519
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Kaneko, Kazumi
A1  - Matsuo, Akira
A1  - Wagner, Torsten
A1  - Kanoh, Shiníchiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Miniaturized chemical imaging sensor system using an OLED display panel
JF  - Sensors and Actuators B: Chemical
N2  - The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the current–voltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.
KW  - LAPS
KW  - Light-addressable potentiometric sensor
KW  - Chemical imaging sensor
KW  - Organic light-emitting diode display
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2011.02.029
SN  - 0925-4005
N1  - Part of special issue "Eurosensors XXIV, 2010"
VL  - 170
SP  - 82
EP  - 87
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Ronkel, F.
A1  - Crott, M.
A1  - Thust, M. (u.a.)
T1  - Miniaturization of potentiometric sensors using porous silicon microtechnology
JF  - Electrochimica Acta. 42 (1997), H. 22
Y1  - 1997
SN  - 0013-4686
SP  - 3185
EP  - 3193
ER  - 
TY  - JOUR
A1  - Simonis, A.
A1  - Dawgul, M.
A1  - Lüth, H.
A1  - Schöning, Michael Josef
T1  - Miniaturised reference electrodes for field-effect sensors compatible to silicon chip technology
JF  - Electrochimica Acta. 51 (2005), H. 5
Y1  - 2005
SN  - 0013-4686
U6  - http://dx.doi.org/10.1016/j.electacta.2005.04.063
SP  - 930
EP  - 937
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Näther, Niko
A1  - Auger, V.
A1  - Poghossian, Arshak
A1  - Koudelka-Hep, M.
T1  - Miniaturised flow-through cell with integrated capacitive EIS sensor fabricated at wafer level using Si and SU-8 technologies
JF  - Sensors and Actuators B. 108 (2005), H. 1-2
Y1  - 2005
SN  - 0925-4005
N1  - Proceedings of the Tenth International Meeting on Chemical Sensors — IMCS - 10 2004
SP  - 986
EP  - 992
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Ingebrandt, S.
A1  - Yeung, C.-K.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Microsensors based on ion-sensitive field-effect transistors for biomedical applications
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1036
EP  - 1037
ER  - 
TY  - JOUR
A1  - Moritz, W.
A1  - Yoshinobu, T.
A1  - Finger, F.
A1  - Krause, S.
A1  - Xu, M.
A1  - Schöning, Michael Josef
T1  - Microscopy of impedance and surface ion concentrations
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1000
EP  - 1001
ER  - 
TY  - JOUR
A1  - Leinhos, Marcel
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Micromachined multi-parameter sensor chip for the control of polymer-degradation medium
JF  - Physica Status Solidi (A) : special issue on engineering and functional interfaces
N2  - It is well known that the degradation environment can strongly influence the biodegradability and kinetics of biodegradation processes of polymers. Therefore, besides the monitoring of the degradation process, it is also necessary to control the medium in which the degradation takes place. In this work, a micromachined multi-parameter sensor chip for the control of the polymer-degradation medium has been developed. The chip combines a capacitive field-effect pH sensor, a four-electrode electrolyte-conductivity sensor and a thin-film Pt-temperature sensor. The results of characterization of individual sensors are presented. In addition, the multi-parameter sensor chip together with an impedimetric polymer-degradation sensor was simultaneously characterized in degradation solutions with different pH and electrolyte conductivity. The obtained results demonstrate the feasibility of the multi-parameter sensor chip for the control of the polymer-degradation medium.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330364
SN  - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1346
EP  - 1351
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Miyamoto, Ko-ichiro
A1  - Shigihara, Noriko
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Microfluidic systems with free definable sensor spots by an integrated light-addressable potentiometric sensor
JF  - Procedia Engineering. 25 (2011)
Y1  - 2011
SN  - 1877-7058
N1  - EurosensorsXXV ; Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece
SP  - 791
EP  - 794
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Raue, Markus
A1  - Schusser, Sebastian
A1  - Jeitner, C.
A1  - Breuer, L.
A1  - Wagner, P.
A1  - Poghossian, Arshak
A1  - Förster, Arnold
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
T1  - Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films
JF  - Physica Status Solidi  (a)
N2  - Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100763
SN  - 1862-6319
VL  - 209
IS  - 5
SP  - 839
EP  - 845
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Arida, Hassan
A1  - Mohsen, Q.
A1  - Schöning, Michael Josef
T1  - Microfabrication, characterization and analytical application of a new thin-film silver microsensor
JF  - Electrochimica Acta. 54 (2009), H. 13
Y1  - 2009
SN  - 0013-4686
SP  - 3543
EP  - 3547
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Lüth, H.
T1  - Microfabricated semiconductor structures – Advances in (bio-)chemical sensing
JF  - Coupling of biological and electronic systems : proceedings of the 2nd Caesarium, Bonn, November 1 - 3, 2000 / Karl-Heinz Hoffmann, ed.
Y1  - 2002
SN  - 3-540-43699-5
SP  - 79
EP  - 92
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
T1  - Microelectronics contacts (bio-)chemistry – Semiconductor-based sensors
JF  - Biologi Italiani. 8 (2001)
Y1  - 2001
SN  - 0392-2510
SP  - 5
EP  - 10
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Glück, O.
A1  - Schroth, P.
A1  - Schütz, S. (u.a.)
T1  - Microelectrodes, capacitors and BioFETs: Novel trends in silicon-based biochemical sensing
JF  - Biocybernetics and Biomedical Engineering. 19 (1999), H. 1
Y1  - 1999
SN  - 0208-5216
SP  - 105
EP  - 126
ER  - 
TY  - JOUR
A1  - Schmitt, G.
A1  - Werner, C.
A1  - Schöning, Michael Josef
T1  - Microelectrochemical efficiency evaluation of inhibitors for CO2 corrosion of carbon steel under high shear stress gradients
JF  - Corrosion 2002. Conference Proceedings. NACExpo, 57th Annual Conference and Exhibition, Denver, US, Apr 7-11, 2002
Y1  - 2002
N1  - Paper 02280
SP  - 1
EP  - 11
PB  - NACE International
CY  - Houston, Texas
ER  -