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 - JOUR A1 - Buniatyan, V. A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Aroutiounian, V. M. A1 - Schöning, Michael Josef T1 - BaxSr1-x TiO3/pc-Si heterojunction capacitance JF - Armenian journal of physics Y1 - 2013 SN - 1829-1171 VL - 6 IS - 4 SP - 188 EP - 197 PB - National Academy of Sciences of Armenia CY - Yerevan ER - TY - JOUR A1 - Schusser, Sebastian A1 - Bäcker, Matthias A1 - Krischer, M. A1 - Wenzel, L. A1 - Leinhos, Marcel A1 - Poghossian, Arshak A1 - Biselli, Manfred A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor JF - Procedia Engineering N2 - A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers. KW - Field-effect sensor KW - enzymatic (bio)degradation KW - poly(d, l-lactic acid) KW - in-situ monitoring KW - impedance spectroscopy Y1 - 2014 U6 - https://doi.org/10.1016/j.proeng.2014.11.689 SN - 1877-7058 N1 - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014> VL - 87 SP - 1314 EP - 1317 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Label-free sensing of biomolecules with field-effect devices for clinical applications JF - Electroanalysis N2 - Among the variety of transducer concepts proposed for label-free detection of biomolecules, the semiconductor field-effect device (FED) is one of the most attractive platforms. As medical techniques continue to progress towards diagnostic and therapies based on biomarkers, the ability of FEDs for a label-free, fast and real-time detection of multiple pathogenic and physiologically relevant molecules with high specificity and sensitivity offers very promising prospects for their application in point-of-care and personalized medicine for an early diagnosis and treatment of diseases. The presented paper reviews recent advances and current trends in research and development of different FEDs for label-free, direct electrical detection of charged biomolecules by their intrinsic molecular charge. The authors are mainly focusing on the detection of the DNA hybridization event, antibody-antigen affinity reaction as well as clinically relevant biomolecules such as cardiac and cancer biomarkers. Y1 - 2014 U6 - https://doi.org/10.1002/elan.201400073 SN - 1521-4109 (E-Journal); 1040-0397 (Print) VL - 26 IS - 6 SP - 1197 EP - 1213 PB - Wiley-VCH CY - Weinheim 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 - CHAP A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Buniatyan, V. A1 - Schöning, Michael Josef T1 - Multi-parameter detection for supporting monitoring and control of biogas processes in agriculture 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 - 5 PB - VDE-Verl. CY - Berlin ER - TY - CHAP A1 - Schöning, Michael Josef A1 - Poghossian, Arshak A1 - Glück, Olaf A1 - Thust, Marion T1 - Electrochemical methods for the determination of chemical variables in aqueous media T2 - Measurement, instrumentation, and sensors handbook / ed. by John G. Webster [u.a.] Vol. 2 : Electromagnetic, optical, radiation, chemical, and biomedical measurement Y1 - 2014 SN - 978-1-4398-4891-3 SP - 55-1 EP - 55-54 PB - CRC Pr. CY - Boca Raton, Fla. ER - TY - CHAP A1 - Schöning, Michael Josef A1 - Poghossian, Arshak A1 - Glück, Olaf A1 - Thust, Marion T1 - Electrochemical composition measurement T2 - Measurement, instrumentation, and sensors handbook: electromagnetic, optical, radiation, chemical, and biomedical measuremen Y1 - 2014 SN - 978-1-4398-4891-3 SP - 55-1 EP - 55-54 PB - CRC Pr. CY - Boca Raton, Fa. ET - 2nd ed. ER - TY - CHAP A1 - Buniatyan, V. V. A1 - Huck, Christina A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Rustamyan, L. G. A1 - Hovnikyan, H. H. T1 - Equivalent circuit and optimization of impedance characteristics of an electrolyte conductivity sensor T2 - Proceedings of State Engineering University Armenia : Series Information technologies, electronics, radio engineering Y1 - 2014 VL - Iss. 17 IS - No. 1 SP - 69 EP - 76 ER - TY - JOUR A1 - Bronder, Thomas A1 - Wu, Chunsheng A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies JF - Procedia Engineering N2 - Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride). KW - LAPS KW - lable-free detection KW - DNA hybridization KW - field-effect sensor Y1 - 2014 U6 - https://doi.org/10.1016/j.proeng.2014.11.647 SN - 1877-7058 N1 - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014> VL - 87 SP - 755 EP - 758 PB - Elsevier CY - Amsterdam ER -