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 - 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 - 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 - Poghossian, Arshak A1 - Weil, M. H. A1 - Bäcker, Matthias A1 - Mayer, D. A1 - Schöning, Michael Josef T1 - Field-effect Devices Functionalised with Gold-Nanoparticle/Macromolecule Hybrids: New Opportunities for a Label-Free Biosensing JF - Procedia Engineering N2 - Field-effect capacitive electrolyte-insulator-semiconductor (EIS) sensors functionalised with citrate-capped gold nanoparticles (AuNP) have been used for the electrostatic detection of macromolecules by their intrinsic molecular charge. The EIS sensor detects the charge changes in the AuNP/macromolecule hybrids induced by the adsorption or binding events. A feasibility of the proposed detection scheme has been exemplary demonstrated by realising EIS sensors for the detection of poly-D-lysine molecules. Y1 - 2012 U6 - http://dx.doi.org/10.1016/j.proeng.2012.09.136 SN - 1877-7058 N1 - Part of special issue "26th European Conference on Solid-State Transducers, EUROSENSOR 2012" IS - 47 SP - 273 EP - 276 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Trattner, Barbara A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Stütz, Evamaria A1 - Schmitt-Landsiedel, Doris A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment JF - Sensors and actuators. B: Chemical Y1 - 2013 SN - 1873-3077 (E-Journal); 0925-4005 (Print) VL - Vol. 182 SP - 58 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schusser, Sebastian A1 - Menzel, S. A1 - Bäcker, Matthias A1 - Leinhos, Marcel A1 - Poghossian, Arshak A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Degradation of thin poly(lactic acid) films: characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements JF - Electrochimica Acta Y1 - 2013 SN - 1873-3859 (E-Journal); 0013-4686 (Print) VL - Vol. 113 SP - 779 EP - 784 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bäcker, Matthias A1 - Schusser, Sebastian A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Degradationsverhalten bioabbaubarer Polymere : siliziumbasierte Sensorik zur Überwachung JF - GIT Labor-Fachzeitschrift Y1 - 2013 SN - 0016-3538 SP - 32 EP - 33 PB - Wiley-VCH CY - Weinheim 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 - CHAP A1 - Wu, Chunsheng A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Bronder, Thomas A1 - Bäcker, Matthias A1 - Wang, Ping A1 - Schöning, Michael Josef T1 - An application of a scanning light-addressable potentiometric sensor for label-free DNA detection T2 - 11. Dresdner Sensor-Symposium : 9.-11.12.2013 Y1 - 2013 SN - 978-3-9813484-5-3 SP - 164 EP - 168 ER - TY - CHAP A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Bäcker, Matthias A1 - Zander, W. A1 - Schubert, J. A1 - Sukoyan, L. H. A1 - Begoyan, V. 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 - 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 - 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 - http://dx.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 - Bäcker, Matthias A1 - Kramer, F. A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Bratov, A. A1 - Abramova, N. A1 - Schöning, Michael Josef T1 - Planar and 3D interdigitated electrodes for biosensing applications: The impact of a dielectric barrier on the sensor properties JF - Physica Status Solidi (A) - Applications and Materials Science N2 - Planar and three-dimensional (3D) interdigitated electrodes (IDE) with electrode digits separated by an insulating barrier of different heights were electrochemically characterized and compared in terms of their sensing properties. Due to the impact of the surface resistance, both types of IDE structures display a non-linear behavior in low-ionic strength solutions. The experimental data were fitted to an electrical equivalent circuit and interpreted taking into account the surface-charge-governed properties. The effect of a charged polyelectrolyte layer electrostatically assembled onto the sensor surface on the surface resistance in solutions with different KCl concentration is studied. In case of the same electrode footprint, 3D-IDEs show a larger cell constant and a higher sensitivity to molecular adsorption than that of planar IDEs. The obtained results demonstrate the potential of 3D-IDEs as a new transducer structure for a direct label-free sensing of charged molecules. Y1 - 2014 U6 - http://dx.doi.org/10.1002/pssa.201330416 SN - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print) VL - 211 IS - 6 SP - 1357 EP - 1363 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Bäcker, Matthias A1 - Chaudhuri, S. A1 - Zander, W. A1 - Schubert, J. A1 - Begoyan, V. 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 - http://dx.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 - 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 - http://dx.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 - 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 - CHAP A1 - Bäcker, Matthias A1 - Schusser, Sebastian A1 - Leinhos, Marcel A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Sensor system for the monitoring of degradation processes of biodegradable biopolymers T2 - Sensoren und Messsysteme 2014 ; Beiträge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in Nürnberg. (ITG-Fachbericht ; 250) Y1 - 2014 SN - 978-3-8007-3622-5 SP - 1 EP - 4 PB - VDE-Verl. CY - Düsseldorf 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 - http://dx.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 - 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 - http://dx.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 - Huck, Christina A1 - Poghossian, Arshak A1 - Bäcker, Matthias A1 - Reisert, Steffen A1 - Schubert, J. A1 - Zander, W. A1 - Begoyan, V. K. A1 - Buniatyan, V. V. A1 - Schöning, Michael Josef T1 - Chemical sensors based on a high-k perovskite oxide of barium strontium titanate JF - Procedia Engineering 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 for liquids. In this work, BST films have been applied as a sensitive transducer material for a label-free detection of adsorbed charged macromolecules (positively charged polyelectrolytes) and concentration of hydrogen peroxide vapor as well as protection insulator layer for a contactless electrolyte-conductivity sensor. The experimental results of characterization of individual sensors are presented. Special emphasis is devoted towards the development of a capacitively-coupled contactless electrolyte-conductivity sensor. KW - barium strontium titanate KW - high-k material KW - contactless conductivity sensor KW - multi-functional material KW - hydrogen peroxide Y1 - 2014 U6 - http://dx.doi.org/10.1016/j.proeng.2014.11.258 SN - 1877-7058 N1 - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014> VL - 87 SP - 28 EP - 31 PB - Elsevier CY - Amsterdam ER -