TY - JOUR A1 - Arreola, Julio A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Effect of O2 plasma on properties of electrolyte-insulator-semiconductor structures JF - physica status solidi a : applications and materials sciences N2 - Prior to immobilization of biomolecules or cells onto biosensor surfaces, the surface must be physically or chemically activated for further functionalization. Organosilanes are a versatile option as they facilitate the immobilization through their terminal groups and also display self-assembly. Incorporating hydroxyl groups is one of the important methods for primary immobilization. This can be done, for example, with oxygen plasma treatment. However, this treatment can affect the performance of the biosensors and this effect is not quite well understood for surface functionalization. In this work, the effect of O2 plasma treatment on EIS sensors was investigated by means of electrochemical characterizations: capacitance–voltage (C–V) and constant capacitance (ConCap) measurements. After O2 plasma treatment, the potential of the EIS sensor dramatically shifts to a more negative value. This was successfully reset by using an annealing process. KW - surface functionalization KW - O2 plasma KW - hydroxylation KW - electrolyte-insulator semiconductor sensor (EIS) KW - annealing Y1 - 2017 U6 - http://dx.doi.org/10.1002/pssa.201700025 SN - 1862-6319 VL - 214 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Moreno, Lia A1 - Dosev, D. A1 - Bratov, A. A1 - Dominguez, C. A1 - Schöning, Michael Josef A1 - Kloock, Joachim P. T1 - Effect of electrical properties of the surrounding medium on the response of an interdigitated electrode array with chalcogenide glass film T2 - XX Eurosensors : 20th anniversary ; Göteborg, Sweden, 17 - 20 September 2006 ; [proceedings]. - Vol. 1 Y1 - 2006 SN - 978-91-631-9280-7 N1 - Paper number: T1A-P22 SP - 384 EP - 385 CY - Göteborg ER - TY - JOUR A1 - Abulnaga, El-Hussiny A1 - Pinkenburg, Olaf A1 - Schiffels, Johannes A1 - E-Refai, Ahmed A1 - Buckel, Wolfgang A1 - Selmer, Thorsten T1 - Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli JF - Journal of bacteriology Y1 - 2013 SN - 1098-5530 [E-Journal] SN - 0021-9193 [Print] VL - 195 IS - 16 SP - 3704 EP - 3713 ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Schubert, Jürgen A1 - Schöning, Michael Josef T1 - Dünnschichtsensoren für die Schwermetallanalytik : Mikroelektroden auf Chalkogenidglasbasis JF - GIT Labor-Fachzeitschrift N2 - Die Detektion von Schadstoffen repräsentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte Dünnschichtsensoren bieten eine kostengünstige Möglichkeit, „online“-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuführen. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgläsern zur Detektion von Schwermetallen in wässrigen Medien vorgestellt. Y1 - 2012 IS - 4 SP - 285 EP - 287 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Schubert, Jürgen A1 - Schöning, Michael Josef T1 - Dünnschichtsensoren für die Schwermetallanalytik JF - GIT : Labor-Fachzeitschrift N2 - Die Detektion von Schadstoffen repräsentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte Dünnschichtsensoren bieten eine kostengünstige Möglichkeit, „online“-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuführen. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgläsern zur Detektion von Schwermetallen in wässrigen Medien vorgestellt. Y1 - 2012 SN - 0016-3538 VL - 56 IS - 4 SP - 285 EP - 287 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Wang, Josepf A1 - Krause, Robin A1 - Block, Kirstin A1 - Musameh, Mustafa A1 - Mulchandani, Ashok A1 - Mulchandani, Priti A1 - Chen, Wilfred T1 - Dual amperometric-potentiometric biosensor detection system for monitoring organophosphorus neurotoxins JF - Analyica Chimica Acta. 469 (2002), H. 2 Y1 - 2002 SN - 0378-4304 SP - 197 EP - 203 ER - TY - CHAP A1 - Wu, Chunsheng A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - DNA-hybridization detection using light-addressable potentiometric sensor modified with gold layer 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 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Scheja, Sabrina A1 - Wu, Chunsheng A1 - Keusgen, Michael A1 - Mewes, Dieter A1 - Schöning, Michael Josef T1 - DNA Immobilization and Hybridization Detection by the Intrinsic Molecular Charge Using Capacitive Field-Effect Sensors Modified with a Charged Weak Polyelectrolyte Layer JF - Applied Materials & Interfaces N2 - Miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge favor the semiconductor field-effect platform as one of the most attractive approaches for the development of label-free DNA chips. In this work, a capacitive field-effect EIS (electrolyte–insulator–semiconductor) sensor covered with a layer-by-layer prepared, positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was used for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization. The negatively charged probe single-stranded DNA (ssDNA) molecules were electrostatically adsorbed onto the positively charged PAH layer, resulting in a preferentially flat orientation of the ssDNA molecules within the Debye length, thus yielding a reduced charge-screening effect and a higher sensor signal. Each sensor-surface modification step (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), reducing an unspecific adsorption by a blocking agent, incubation with noncomplementary DNA (ncDNA) solution) was monitored by means of capacitance–voltage and constant-capacitance measurements. In addition, the surface morphology of the PAH layer was studied by atomic force microscopy and contact-angle measurements. High hybridization signals of 34 and 43 mV were recorded in low-ionic strength solutions of 10 and 1 mM, respectively. In contrast, a small signal of 4 mV was recorded in the case of unspecific adsorption of fully mismatched ncDNA. The density of probe ssDNA and dsDNA molecules as well as the hybridization efficiency was estimated using the experimentally measured DNA immobilization and hybridization signals and a simplified double-layer capacitor model. The results of field-effect experiments were supported by fluorescence measurements, verifying the DNA-immobilization and hybridization event. Y1 - 2015 U6 - http://dx.doi.org/10.1021/acsami.5b05146 VL - 36 IS - 7 SP - 20068 EP - 20075 PB - American Chemical Society CY - Washington, DC ER - TY - JOUR A1 - Gamella, Maria A1 - Zakharchenko, Andrey A1 - Guz, Nataliia A1 - Masi, Madeline A1 - Minko, Sergiy A1 - Kolpashchikov, Dmitry M. A1 - Iken, Heiko A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - DNA computing system activated by electrochemically triggered DNA realease from a polymer-brush-modified electrode array JF - Electroanalysis N2 - An array of four independently wired indium tin oxide (ITO) electrodes was used for electrochemically stimulated DNA release and activation of DNA-based Identity, AND and XOR logic gates. Single-stranded DNA molecules were loaded on the mixed poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA)/poly(methacrylic acid) (PMAA) brush covalently attached to the ITO electrodes. The DNA deposition was performed at pH 5.0 when the polymer brush is positively charged due to protonation of tertiary amino groups in PDMAEMA, thus resulting in electrostatic attraction of the negatively charged DNA. By applying electrolysis at −1.0 V(vs. Ag/AgCl reference) electrochemical oxygen reduction resulted in the consumption of hydrogen ions and local pH increase near the electrode surface. The process resulted in recharging the polymer brush to the negative state due to dissociation of carboxylic groups of PMAA, thus repulsing the negatively charged DNA and releasing it from the electrode surface. The DNA release was performed in various combinations from different electrodes in the array assembly. The released DNA operated as input signals for activation of the Boolean logic gates. The developed system represents a step forward in DNA computing, combining for the first time DNA chemical processes with electronic input signals. Y1 - 2017 U6 - http://dx.doi.org/10.1002/elan.201600389 SN - 1521-4109 VL - 29 IS - 2 SP - 398 EP - 408 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Bongaerts, Johannes A1 - Esser, Simon A1 - Lorbach, Volker A1 - Al-Momani, Lóay A1 - Müller, Michael A. A1 - Franke, Dirk A1 - Grondal, Christoph A1 - Kurutsch, Anja A1 - Bujnicki, Robert A1 - Takors, Ralf A1 - Raeven, Leon A1 - Wubbolts, Marcel A1 - Bovenberg, Roel A1 - Nieger, Martin A1 - Schürmann, Melanie A1 - Trachtmann, Natalie A1 - Kozak, Stefan A1 - Sprenger, Georg A. A1 - Müller, Michael T1 - Diversity-oriented production of metabolites derived from chorismate and their use in organic synthesis JF - Angewandte Chemie International Edition Y1 - 2011 SN - 1521-3773 (E-Journal); 0570-0833 (Print); 1433-7851 (Print) VL - Vol. 50 IS - Iss. 34 SP - 7781 EP - 7786 PB - Wiley CY - Weinheim ER -