TY - JOUR A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Combined amperometric/field-effect sensor for the detection of dissolved hydrogen JF - Sensors and actuators B: Chemical N2 - Real-time and reliable monitoring of the biogas process is crucial for a stable and efficient operation of biogas production in order to avoid digester breakdowns. The concentration of dissolved hydrogen (H₂) represents one of the key parameters for biogas process control. In this work, a one-chip integrated combined amperometric/field-effect sensor for monitoring the dissolved H₂ concentration has been developed for biogas applications. The combination of two different transducer principles might allow a more accurate and reliable measurement of dissolved H₂ as an early warning indicator of digester failures. The feasibility of the approach has been demonstrated by simultaneous amperometric/field-effect measurements of dissolved H₂ concentrations in electrolyte solutions. Both, the amperometric and the field-effect transducer show a linear response behaviour in the H₂ concentration range from 0.1 to 3% (v/v) with a slope of 198.4 ± 13.7 nA/% (v/v) and 14.9 ± 0.5 mV/% (v/v), respectively. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2012.10.050 SN - 0925-4005 N1 - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors" VL - 187 SP - 168 EP - 173 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schusser, Sebastian A1 - Poghossian, Arshak A1 - Bäcker, Matthias A1 - Leinhos, Marcel A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Characterization of biodegradable polymers with capacitive field-effect sensors JF - Sensors and actuators B: Chemical N2 - In vitro studies of the degradation kinetic of biopolymers are essential for the design and optimization of implantable biomedical devices. In the presented work, a field-effect capacitive sensor has been applied for the real-time and in situ monitoring of degradation processes of biopolymers for the first time. The polymer-covered field-effect sensor is, in principle, capable to detect any changes in bulk, surface and interface properties of the polymer induced by degradation processes. The feasibility of this approach has been experimentally proven by using the commercially available biomedical polymer poly(D,L-lactic acid) (PDLLA) as a model system. PDLLA films of different thicknesses were deposited on the Ta₂O₅-gate surface of the field-effect structure from a polymer solution by means of spin-coating method. The polymer-modified field-effect sensors have been characterized by means of capacitance–voltage and impedance-spectroscopy method. The degradation of the PDLLA was accelerated by changing the degradation medium from neutral (pH 7.2) to alkaline (pH 9) condition, resulting in drastic changes in the capacitance and impedance spectra of the polymer-modified field-effect sensor. KW - Impedance spectroscopy KW - C–V method KW - Real-time monitoring KW - Poly(d,l-lacticacid) KW - (Bio)degradation KW - Field-effect sensor Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.snb.2012.07.099 SN - 0925-4005 N1 - Part of special issue "Selected Papers from the 14th International Meeting on Chemical Sensors" VL - 187 SP - 2 EP - 7 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 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Cherstvy, Andrey G. A1 - Pedraza, Angela M. A1 - Ingebrandt, Sven A1 - Schöning, Michael Josef T1 - Label-free electrical detection of DNA by means of field-effect nanoplate capacitors: Experiments and modeling JF - Physica Status Solidi (a) N2 - Label-free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization/denaturation by means of an array of individually addressable field-effect-based nanoplate silicon-on-insulator (SOI) capacitors modified with gold nanoparticles (Au-NP) is investigated. The proposed device detects charge changes on Au-NP/DNA hybrids induced by the hybridization or denaturation event. DNA hybridization was performed in a high ionic-strength solution to provide a high hybridization efficiency. On the other hand, to reduce the screening of the DNA charge by counter ions and to achieve a high sensitivity, the sensor signal induced by the hybridization and denaturation events was measured in a low ionic-strength solution. High sensor signals of about 120, 90, and 80 mV were registered after the DNA hybridization, denaturation, and re-hybridization events, respectively. Fluorescence microscopy has been applied as reference method to verify the DNA immobilization, hybridization, and denaturation processes. An electrostatic charge-plane model for potential changes at the gate surface of a nanoplate field-effect sensor induced by the DNA hybridization has been developed taking into account both the Debye length and the distance of the DNA charge from the gate surface. Y1 - 2012 U6 - http://dx.doi.org/10.1002/pssa.201100710 SN - 1862-6319 VL - 209 SP - 925 EP - 934 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Bäcker, Matthias A1 - Rakowski, D. A1 - Poghossian, Arshak A1 - Biselli, Manfred A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis JF - Journal of Biotechnology N2 - A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses. Y1 - 2013 U6 - http://dx.doi.org/10.1016/j.jbiotec.2012.03.014 SN - 0168-1656 VL - 163 IS - 4 SP - 371 EP - 376 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Schusser, Sebastian A1 - Leinhos, Marcel A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Schöning, Michael Josef ED - Abdelghani, Adnane ED - Schöning, Michael Josef T1 - Biopolymer-degradation monitoring by chip-­based impedance spectroscopy technique T2 - Nanoscale Science and Technology (NS&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012 Y1 - 2012 SP - 47 EP - 47 ER - TY - CHAP A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef ED - Abdelghani, Adnane ED - Schöning, Michael Josef T1 - (Bio-­)chemical sensor array based on nanoplate SOI capacitors T2 - Nanoscale Science and Technology (NS&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012 Y1 - 2012 SP - 31 EP - 31 ER - TY - JOUR A1 - Huck, Christina A1 - Jolly, Christina A1 - Wagner, Patrick A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - One-chip integrated dual amperometric/field-effect sensor for the detection of dissolved hydrogen JF - Procedia Engineering. 25 (2011) Y1 - 2011 SN - 1877-7058 N1 - EurosensorsXXV ; Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece SP - 1161 EP - 1164 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Poghossian, Arshak A1 - Malzahn, K. A1 - Abouzar, Maryam H. A1 - Mehndiratta, P. A1 - Katz, E. A1 - Schöning, Michael Josef T1 - Integration of biomolecular logic gates with field-effect transducers JF - Electrochimica Acta. 56 (2011), H. 26 Y1 - 2011 SN - 0013-4686 SP - 9661 EP - 9665 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Delle, L. A1 - Poghossian, Arshak A1 - Biselli, Manfred A1 - Zang, Werner A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Electrochemical sensor array for bioprocess monitoring JF - Electrochimica Acta (2011) Y1 - 2011 VL - 56 IS - 26 SP - 9673 EP - 9678 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gasparyan, Ferdinand V. A1 - Poghossian, Arshak A1 - Vitusevich, Svetlana A. A1 - Petrychuk, Mykhaylo V. A1 - Sydoruk, Viktor A. A1 - Siqueira, José R. Jr. A1 - Oliveira, Osvaldo N. Jr. A1 - Offenhäusser, Andreas A1 - Schöning, Michael Josef T1 - Low-Frequency Noise in Field-Effect Devices Functionalized With Dendrimer/Carbon-Nanotube Multilayers JF - IEEE Sensors Journal. 11 (2011), H. 1 Y1 - 2011 SN - 1530-437X SP - 142 EP - 149 PB - IEEE CY - New York ER - TY - JOUR A1 - Poghossian, Arshak A1 - Wagner, H. A1 - Schöning, Michael Josef T1 - Automatisiertes „wafer level“-Testsystem zur Charakterisierung von siliziumbasierten Chemo- und Biosensoren JF - Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vorträge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in Nürnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA) Y1 - 2010 SN - 978-3-8007-3260-9 N1 - Fachtagung Sensoren und Messsysteme 15, 2010, Nürnberg ; Gesellschaft Mess- und Automatisierungstechnik SP - 89 EP - 92 PB - VDE Verlag CY - Berlin ER - TY - JOUR A1 - Biselli, Manfred A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Schnitzler, Thomas A1 - Zang, Werner A1 - Wagner, P. T1 - Entwicklung eines modularen festkörperbasierten Sensorsystems für die Überwachung von Zellkulturfermenationen JF - Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vorträge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in Nürnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA) Y1 - 2010 SN - 978-3-8007-3260-9 N1 - Fachtagung Sensoren und Messsysteme 15, 2010, Nürnberg ; Gesellschaft Mess- und Automatisierungstechnik SP - 688 EP - 691 PB - VDE Verlag CY - Berlin ER - TY - JOUR A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Schnitzler, Thomas A1 - Biselli, Manfred A1 - Zang, Werner A1 - Wagner, P. T1 - Entwicklung eines modularen festkörperbasierten Sensorsystems für die Überwachung von Zellkulturfermentationen JF - Sensoren und Messsysteme 2010 [Elektronische Ressource] : Vorträge der 15. ITG/GMA-Fachtagung vom 18. bis 19. Mai 2010 in Nürnberg / Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA) Y1 - 2010 SN - 978-3-8007-3260-9 N1 - Fachtagung Sensoren und Messsysteme 15, 2010, Nürnberg ; Gesellschaft Mess- und Automatisierungstechnik SP - 688 EP - 698 PB - VDE Verlag CY - Berlin ER - TY - JOUR A1 - Gun, Jenny A1 - Gutkin, Vitaly A1 - Lev, Ovadia A1 - Boyen, Hans-Gerd A1 - Saitner, Marc A1 - Wagner, Patrick A1 - Olieslaeger, Marc D´ A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Tracing gold nanoparticle charge by electrolyte-insulator-semiconductor devices JF - Journal of Physical Chemistry C. 115 (2011), H. 11 Y1 - 2011 SN - 1932-7455 SP - 4439 EP - 4445 PB - American Cemical Society CY - Washington, DC ER - TY - JOUR A1 - Poghossian, Arshak A1 - Wagner, Holger A1 - Schöning, Michael Josef T1 - Functional testing and characterisation of (bio-)chemical sensors on wafer level JF - Sensors and Actuators B: Chemical. 154 (2011), H. 2 Y1 - 2011 SN - 1873-3077 N1 - EUROSENSORS XXIII SP - 169 EP - 173 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Abouzar, Maryam H. A1 - Werner, Moritz A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Capacitance–voltage and impedance-spectroscopy characteristics of nanoplate EISOI capacitors JF - Physica status solidi (a) : applications and material science. 208 (2011), H. 6 Y1 - 2011 SN - 1862-6319 SP - 1327 EP - 1332 PB - Wiley-VCH CY - Berlin ER - TY - JOUR A1 - Bäcker, Matthias A1 - Pouyeshman, S. A1 - Schnitzler, Thomas A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Biselli, Manfred A1 - Schöning, Michael Josef T1 - A silicon-based multi-sensor chip for monitoring of fermentation processes JF - Physica status solidi (a) : applications and material science. 208 (2011), H. 6 Y1 - 2011 SN - 1862-6319 SP - 1364 EP - 1369 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Pedraza, A. M. A1 - Gandhi, D. A1 - Ingebrandt, S. A1 - Moritz, W. A1 - Schöning, Michael Josef T1 - An array of field-effect nanoplate SOI capacitors for (bio-)chemical sensing JF - Biosensors and Bioelectronics. 26 (2011), H. 6 Y1 - 2011 SN - 0956-5663 SP - 3023 EP - 3028 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Abouzar, Maryam H. A1 - Pedraza, A. M. A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Label-free DNA hybridization and denaturation detection by means of field-effect nanoplate SOI capacitors functionalized with gold nanoparticles JF - Procedia Engineering. 5 (2010) Y1 - 2010 SN - 1877-7058 N1 - Proc. Eurosensors XXIV, September 5–8, 2010, Linz, Austria SP - 918 EP - 921 ER -