TY - JOUR A1 - Wu, Chunsheng A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Schöning, Michael Josef T1 - Label-free detection of DNA using light-addressable potentiometric sensor modified with a positively charged polyelectrolyte layer JF - Nanoscale N2 - A multi-spot (16 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al–p-Si–SiO2 structure modified with a weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. To achieve a preferentially flat orientation of DNA strands and thus, to reduce the distance between the DNA charge and MLAPS surface, the negatively charged probe single-stranded DNAs (ssDNA) were electrostatically adsorbed onto the positively charged PAH layer using a simple layer-by-layer (LbL) technique. In this way, more DNA charge can be positioned within the Debye length, yielding a higher sensor signal. The surface potential changes in each spot induced due to the surface modification steps (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), non-specific adsorption of mismatched ssDNA) were determined from the shifts of photocurrent–voltage curves along the voltage axis. A high sensor signal of 83 mV was registered after immobilization of probe ssDNA onto the PAH layer. The hybridization signal increases from 5 mV to 32 mV with increasing the concentration of cDNA from 0.1 nM to 5 μM. In contrast, a small signal of 5 mV was recorded in the case of non-specific adsorption of fully mismatched ssDNA (5 μM). The obtained results demonstrate the potential of the MLAPS in combination with the simple and rapid LbL immobilization technique as a promising platform for the future development of multi-spot light-addressable label-free DNA chips with direct electrical readout. Y1 - 2015 U6 - http://dx.doi.org/10.1039/C4NR07225A VL - 14 IS - 7 SP - 6143 EP - 6150 PB - Royal Society of Chemistry (RSC) CY - Cambridge 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 - http://dx.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 - TY - JOUR A1 - Poghossian, Arshak A1 - Ingebrandt, S. A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef T1 - Label-free detection of charged macromolecules by using a field-effect-based sensor platform: Experiments and possible mechanisms of signal generation JF - Applied Physics A: Materials Science & Processing. 87 (2007), H. 3 Y1 - 2007 SN - 0947-8396 N1 - Special Issue “From Surface Science to Nanoscale Devices” SP - 517 EP - 524 ER - TY - BOOK A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Label-free biosensing: advanced materials, devices and applications Y1 - 2018 SN - 978-3-319-75219-8 PB - Springer CY - Cham ER - TY - JOUR A1 - Mourzina, Y. A1 - Mai, T. A1 - Poghossian, Arshak A1 - Ermolenko, Y. A1 - Yoshinobu, T. A1 - Vlasov, Y. A1 - Iwasaki, H. A1 - Schöning, Michael Josef T1 - K+-selective field-effect sensors as transducers for bioelectronic applications JF - Electrochimica Acta. 48 (2003), H. 20-22 Y1 - 2003 SN - 0013-4686 SP - 3333 EP - 3339 ER - TY - CHAP A1 - Beging, Stefan A1 - Poghossian, Arshak A1 - Mlynek, D. A1 - Hataihimakul, S. A1 - Pedraza, A. A1 - Dhawan, S. A1 - Laube, N. A1 - Kleinen, L. A1 - Baldsiefen, G. A1 - Busch, H. A1 - Schöning, Michael Josef T1 - Ion-selective sensors for the determination of the risk of urinary stone formation T2 - Micro- and Nanosystems in biochemical diagnosis : Principles and applications Y1 - 2010 SP - 74 EP - 80 CY - Warsaw ER - TY - JOUR A1 - Poghossian, Arshak A1 - Krämer, Melina A1 - Abouzar, Maryam H. A1 - Pita, Marcos A1 - Katz, Evgeny A1 - Schöning, Michael Josef T1 - Interfacing of biocomputing systems with silicon chips: Enzyme logic gates based on field-effect devices JF - Procedia Chemistry. 1 (2009), H. 1 Y1 - 2009 SN - 1876-6196 N1 - Proceedings of the Eurosensors XXIII conference ; Eurosensors 23 SP - 682 EP - 685 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 - Rolka, David A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Integration of a capacitive EIS sensor into a FIA system for pH and penicillin determination JF - Sensors. 4 (2004) Y1 - 2004 SN - 1424-8220 SP - 84 EP - 94 ER - 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 - http://dx.doi.org/10.1002/pssa.201200941 SN - 1521-396X ; 0031-8965 VL - 210 IS - 5 SP - 905 EP - 910 PB - Wiley CY - Weinheim ER -