TY - JOUR A1 - Schusser, Sebastian A1 - Leinhos, Marcel A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers JF - Physica Status Solidi (A) N2 - Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution. Y1 - 2013 U6 - https://doi.org/10.1002/pssa.201200941 SN - 1521-396X ; 0031-8965 VL - 210 IS - 5 SP - 905 EP - 910 PB - Wiley 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 - Schreiber, Marc A1 - Hirtbach, Stefan A1 - Kraft, Bodo A1 - Steinmetzler, Andreas ED - Kowalewski, Stefan T1 - Software in the city: visual guidance through large scale software projects T2 - Software Engineering 2013 : Fachtagung des GI-Fachbereichs Softwaretechnik, 26. Februar-1. März 2013 in Aachen. (GI-Edition ; 213) Y1 - 2013 SN - 978-3-88579-607-7 ; 978-3-88579-609-1 SP - 213 EP - 224 PB - Ges. für Informatik CY - Bonn ER - TY - CHAP A1 - Savitskaya, Irina S. A1 - Kistaubayeva, Aida S. A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya A1 - Zhubanova, Azhar A. T1 - Performance of Bio-Composite Carbonized Materials in Probiotic Applications T2 - World Academy of Science, Engineering and Technology International Journal of Biotechnology and Bioengineering Y1 - 2013 VL - 7 IS - 7 SP - 685 EP - 689 ER - TY - JOUR A1 - Reisert, Steffen A1 - Schneider, Benno A1 - Geissler, Hanno A1 - Gompel, Matthias van A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Multi-sensor chip for the investigation of different types of metal oxides for the detection of H2O2 in the ppm range JF - physica status solidi (a) N2 - In this work, a multi-sensor chip for the investigation of the sensing properties of different types of metal oxides towards hydrogen peroxide in the ppm range is presented. The fabrication process and physical characterization of the multi-sensor chip are described. Pure SnO2 and WO3 as well as Pd- and Pt-doped SnO2 films are characterized in terms of their sensitivity to H2O2. The sensing films have been prepared by drop-coating of water-dispensed nano-powders. A physical characterization, including scanning electron microscopy and X-ray diffraction analysis of the deposited metal-oxide films, was done. From the measurements in hydrogen peroxide atmosphere, it could be shown, that all of the tested metal oxide films are suitable for the detection of H2O2 in the ppm range. The highest sensitivity and reproducibility was achieved using Pt-doped SnO2. Calibration plot of a SnO2, WO3, Pt-, and Pd-doped SnO2 gas sensor for H2O2 concentrations in the ppm range. Y1 - 2013 SN - 1862-6319 VL - 210 IS - 5 SP - 898 EP - 904 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Reisert, Steffen A1 - Geissler, Hanno A1 - Flörke, Rudolf A1 - Weiler, Christian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Characterisation of aseptic sterilisation processes using an electronic nose JF - International journal of nanotechnology Y1 - 2013 SN - 1475-7435 (Print) 7141-8151 (Online) VL - Vol. 10 IS - No. 5-7 SP - 470 EP - 484 PB - Inderscience Enterprises CY - Genève ER - TY - JOUR A1 - Poghossian, Arshak A1 - Weil, M. A1 - Cherstvy, A. G. A1 - Schöning, Michael Josef T1 - Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices JF - Analytical and bioanalytical chemistry N2 - The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte–insulator–semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance–voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed. Y1 - 2013 U6 - https://doi.org/10.1007/s00216-013-6951-9 SN - 1432-1130 ; 1618-2642 VL - 405 IS - 20 SP - 6425 EP - 6436 PB - Springer CY - Berlin ER - TY - JOUR A1 - Pham, Phu Tinh A1 - Staat, Manfred T1 - An Upper Bound Algorithm for Limit and Shakedown Analysis of Bounded Linearly Kinematic Hardening Structures JF - Limit State of Materials and Structures : Direct Methods 2. Saxcé, Géry de (Hrsg.) Y1 - 2013 SN - 978-94-007-5424-9 SP - 71 EP - 87 PB - Springer CY - Dordrecht ER - TY - CHAP A1 - Oberländer, Jan A1 - Reisert, Steffen A1 - Kirchner, Patrick A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Kalorimetrische Gassensoren zur H2O2-Detektion in aseptischen Sterilisationsprozessen T2 - 11. Dresdner Sensor-Symposium : 9.-11.12.2013 Y1 - 2013 SN - 978-3-9813484-5-3 SP - 234 EP - 238 ER - TY - JOUR A1 - Murib, M. S. A1 - Grinsven, B. van A1 - Grieten, L. A1 - Janssens, S. D. A1 - Vermeeren, V. A1 - Eersels, K. A1 - Broeders, J. A1 - Ameloot, Marcel A1 - Michiels, L. A1 - Ceuninck, W. De A1 - Haenen, K. A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates JF - Physica Status Solidi (A). Vol. 210 (2013), iss. 5 Y1 - 2013 SN - 0031-8965 SP - 911 EP - 917 PB - Wiley-VCH CY - Berlin ER -