TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef T1 - Capacitance–voltage and impedance characteristics of field-effect EIS sensors functionalised with polyelectrolyte multilayers JF - IRBM. 29 (2008), H. 2-3 Y1 - 2008 SN - 1959-0318 SP - 149 EP - 154 ER - TY - CHAP A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef ED - Abdelghani, Adnane ED - Schöning, Michael Josef T1 - (Bio-­)chemical sensor array based on nanoplate SOI capacitors T2 - Nanoscale Science and Technology (NS&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012 Y1 - 2012 SP - 31 EP - 31 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Sakkari, M. A1 - Kassab, T. A1 - Han, Y. A1 - Ingebrandt, S. A1 - Offenhäusser, A. A1 - Schöning, Michael Josef T1 - Field-effect sensors for monitoring the layer-by-layer adsorption of charged macromolecules JF - Sensors and Actuators B: Chemical. 118 (2006), H. 1-2 Y1 - 2006 SN - 0925-4005 N1 - Eurosensors XIX - Eurosensors XIX - The 19th European Conference on Solid-State Transducers SP - 163 EP - 170 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Razavi, A. A1 - Bäcker, Matthias A1 - Bijnens, N. A1 - Williams, O. A. A1 - Haenen, K. A1 - Moritz, W. A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Nanocrystalline-diamond thin films with high pH and penicillin sensitivity prepared on a capacitive Si–SiO2 structure JF - Electrochimica Acta. 54 (2009), H. 25 Y1 - 2009 SN - 0013-4686 SP - 5981 EP - 5985 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Christiaens, P. A1 - Williams, O. A. A1 - Haenen, K. A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Sensing charged macromolecules with nanocrystalline diamond-based field-effect capacitive sensors JF - Journal of Contemporary Physics. 43 (2008), H. 2 Y1 - 2008 SN - 1934-9378 N1 - Armenian Academy of Sciences SP - 77 EP - 81 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Christiaens, P. A1 - Williams, O. A. A1 - Haenen, K. A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Nanocrystalline diamond-based field-effect (bio-)chemical sensor JF - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.) Y1 - 2007 SN - 978-3-940046-45-1 N1 - Dresdner Sensor-Symposium <8, 2007, Dresden> ; Dresdner Beiträge zur Sensorik ; 29 SP - 191 EP - 194 PB - TUDpress, Verl. der Wissenschaften CY - Dresden ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Amberger, F. A1 - Mayer, D. A1 - Han, Y. A1 - Ingebrandt, S. A1 - Offenhäusser, A. A1 - Schöning, Michael Josef T1 - Field-effect sensors with charged macromolecules: Characterisation by capacitance–voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods JF - Biosensors and Bioelectronics. 22 (2007), H. 9-10 Y1 - 2007 SN - 0956-5663 N1 - Selected Papers from the Ninth World Congress On Biosensors. Toronto, Canada 10 - 12 May 2006, Alice X. J . Tang SP - 2100 EP - 2107 ER - TY - CHAP A1 - Platen, Johannes A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Microstructured Nanostructures – nanostructuring by means of conventional photolithography and layer-expansion technique N2 - A new and simple method for nanostructuring using conventional photolithography and layer expansion or pattern-size reduction technique is presented, which can further be applied for the fabrication of different nanostructures and nano-devices. The method is based on the conversion of a photolithographically patterned metal layer to a metal-oxide mask with improved pattern-size resolution using thermal oxidation. With this technique, the pattern size can be scaled down to several nanometer dimensions. The proposed method is experimentally demonstrated by preparing nanostructures with different configurations and layouts, like circles, rectangles, trapezoids, “fluidic-channel”-, “cantilever”- and meander-type structures. KW - Biosensor KW - Nanostructuring KW - layer expansion KW - pattern-size reduction KW - self-aligned patterning Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1477 ER - TY - JOUR A1 - Pita, Marcos A1 - Krämer, Melina A1 - Zouh, Jian A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Fernandez, Victor M. A1 - Katz, Evgeny T1 - Optoelectronic Properties of Nanostructured Ensembles Controlled by Biomolecular Logic Systems JF - ACS Nano. 10 (2008), H. 2 Y1 - 2008 SN - 1936-086X SP - 2160 EP - 2166 ER - TY - JOUR A1 - Pilas, Johanna A1 - Yazici, Yasemen A1 - Selmer, Thorsten A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Optimization of an amperometric biosensor array for simultaneous measurement of ethanol, formate, d- and l-lactate JF - Electrochimica Acta N2 - The immobilization of NAD+-dependent dehydrogenases, in combination with a diaphorase, enables the facile development of multiparametric sensing devices. In this work, an amperometric biosensor array for simultaneous determination of ethanol, formate, d- and l-lactate is presented. Enzyme immobilization on platinum thin-film electrodes was realized by chemical cross-linking with glutaraldehyde. The optimization of the sensor performance was investigated with regard to enzyme loading, glutaraldehyde concentration, pH, cofactor concentration and temperature. Under optimal working conditions (potassium phosphate buffer with pH 7.5, 2.5 mmol L-1 NAD+, 2.0 mmol L-1 ferricyanide, 25 °C and 0.4% glutaraldehyde) the linear working range and sensitivity of the four sensor elements was improved. Simultaneous and cross-talk free measurements of four different metabolic parameters were performed successfully. The reliable analytical performance of the biosensor array was demonstrated by application in a clarified sample of inoculum sludge. Thereby, a promising approach for on-site monitoring of fermentation processes is provided. KW - Simultaneous determination KW - Enzymatic biosensor KW - Diaphorase KW - Dehydrogenase Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.electacta.2017.07.119 SN - 0013-4686 VL - 251 SP - 256 EP - 262 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pilas, Johanna A1 - Yazici, Y. A1 - Selmer, Thorsten A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Application of a portable multi-analyte biosensor for organic acid determination in silage JF - Sensors N2 - Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media. Y1 - 2018 U6 - http://dx.doi.org/10.3390/s18051470 SN - 1424-8220 VL - 18 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Pilas, Johanna A1 - Selmer, Thorsten A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Screen-printed carbon electrodes modified with graphene oxide for the design of a reagent-free NAD+-dependent biosensor array JF - Analytical Chemistry Y1 - 2019 U6 - http://dx.doi.org/10.1021/acs.analchem.9b04481 VL - 91 IS - 23 SP - 15293 EP - 15299 PB - ACS Publications CY - Washington ER - TY - JOUR A1 - Pilas, Johanna A1 - Mariano, K. A1 - Keusgen, M. A1 - Selmer, Thorsten A1 - Schöning, Michael Josef T1 - Optimization of an Enzyme-based Multi-parameter Biosensor for Monitoring Biogas Processes JF - Procedia Engineering Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.proeng.2015.08.702 SN - 1877-7058 N1 - Part of special issue "Eurosensors 2015" VL - 120 SP - 532 EP - 535 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pilas, Johanna A1 - Iken, Heiko A1 - Selmer, Thorsten A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Development of a multi‐parameter sensor chip for the simultaneous detection of organic compounds in biogas processes JF - Physica status solidi (a) N2 - An enzyme-based multi-parameter biosensor is developed for monitoring the concentration of formate, d-lactate, and l-lactate in biological samples. The sensor is based on the specific dehydrogenation by an oxidized β-nicotinamide adenine dinucleotide (NAD+)-dependent dehydrogenase (formate dehydrogenase, d-lactic dehydrogenase, and l-lactic dehydrogenase, respectively) in combination with a diaphorase from Clostridium kluyveri (EC 1.8.1.4). The enzymes are immobilized on a platinum working electrode by cross-linking with glutaraldehyde (GA). The principle of the determination scheme in case of l-lactate is as follows: l-lactic dehydrogenase (l-LDH) converts l-lactate into pyruvate by reaction with NAD+. In the presence of hexacyanoferrate(III), the resulting reduced β-nicotinamide adenine dinucleotide (NADH) is then regenerated enzymatically by diaphorase. The electrochemical detection is based on the current generated by oxidation of hexacyanoferrate(II) at an applied potential of +0.3 V vs. an Ag/AgCl reference electrode. The biosensor will be electrochemically characterized in terms of linear working range and sensitivity. Additionally, the successful practical application of the sensor is demonstrated in an extract from maize silage. Y1 - 2015 U6 - http://dx.doi.org/10.1002/pssa.201431894 SN - 1862-6319 VL - 212 IS - 6 SP - 1306 EP - 1312 PB - Wiley CY - Weinheim ER - TY - CHAP A1 - Pijanowska, Dorota G. A1 - Remiszewska, Elzbieta A1 - Pederzolli, Cecilia A1 - Lunelli, Lorenzo A1 - Vendano, Michele A1 - Canteri, Roberto A1 - Dudzinski, Konrad A1 - Kruk, Jerzy A1 - Torbicz, Wladyslaw T1 - Surface modification for microreactor fabrication N2 - In this paper, methods of surface modification of different supports, i.e. glass and polymeric beads for enzyme immobilisation are described. The developed method of enzyme immobilisation is based on Schiff’s base formation between the amino groups on the enzyme surface and the aldehyde groups on the chemically modified surface of the supports. The surface of silicon modified by APTS and GOPS with immobilised enzyme was characterised by atomic force microscopy (AFM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS) and infrared spectroscopy (FTIR). The supports with immobilised enzyme (urease) were also tested in combination with microreactors fabricated in silicon and Perspex, operating in a flow-through system. For microreactors filled with urease immobilised on glass beads (Sigma) and on polymeric beads (PAN), a very high and stable signal (pH change) was obtained. The developed method of urease immobilisation can be stated to be very effective. KW - Biosensor KW - Microreactors KW - surface modification KW - enzyme immobilisation KW - lab-on-a-chip Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1480 ER - TY - CHAP A1 - Pijanowska, Dorota G. A1 - Remiszewska, Elzbieta T1 - pH-based detection of phenylalnine by potentiometric and colorimetric methods N2 - In this paper, methods of sample preparation for potentiometric measurement of phenylalanine are presented. Basing on the spectrophotometric measurements of phenylalanine, the concentrations of reagents of the enzymatic reaction (10 mM L-Phe, 0,4 mM NAD+, 2U L-PheDH) were determined. Then, the absorption spectrum of the reaction product, NADH, was monitored (maximum peak at 340 nm). The results obtained by the spectrophotometric method were compared with the results obtained by the colourimetry, using pH indicators. The above-mentioned two methods will be used as references for potentiometric measurements of phenylalanine concentration. KW - Biosensor KW - Phenylalanine determination KW - enzymatic methods KW - pH-based biosensing Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1536 ER - TY - JOUR A1 - Pieronek, Lukas A1 - Kleefeld, Andreas T1 - On trajectories of complex-valued interior transmission eigenvalues JF - Inverse problems and imaging : IPI N2 - This paper investigates the interior transmission problem for homogeneous media via eigenvalue trajectories parameterized by the magnitude of the refractive index. In the case that the scatterer is the unit disk, we prove that there is a one-to-one correspondence between complex-valued interior transmission eigenvalue trajectories and Dirichlet eigenvalues of the Laplacian which turn out to be exactly the trajectorial limit points as the refractive index tends to infinity. For general simply-connected scatterers in two or three dimensions, a corresponding relation is still open, but further theoretical results and numerical studies indicate a similar connection. KW - Interior transmission problem KW - Eigenvalue trajectories KW - Complex-valued eigenvalues Y1 - 2024 U6 - http://dx.doi.org/10.3934/ipi.2023041 SN - 1930-8337 (Print) SN - 1930-8345 (Online) VL - 18 IS - 2 SP - 480 EP - 516 PB - AIMS CY - Springfield, Mo ER - TY - JOUR A1 - Philipp, Mohr A1 - Efthimiou, Nikos A1 - Pagano, Fiammetta A1 - Kratochwil, Nicolaus A1 - Pizzichemi, Marco A1 - Tsoumpas, Charalampos A1 - Auffray, Etiennette A1 - Ziemons, Karl T1 - Image reconstruction analysis for positron emission tomography with heterostructured scintillators JF - IEEE Transactions on Radiation and Plasma Medical Sciences N2 - The concept of structure engineering has been proposed for exploring the next generation of radiation detectors with improved performance. A TOF-PET geometry with heterostructured scintillators with a pixel size of 3.0×3.1×15 mm3 was simulated using Monte Carlo. The heterostructures consisted of alternating layers of BGO as a dense material with high stopping power and plastic (EJ232) as a fast light emitter. The detector time resolution was calculated as a function of the deposited and shared energy in both materials on an event-by-event basis. While sensitivity was reduced to 32% for 100 μm thick plastic layers and 52% for 50 μm, the CTR distribution improved to 204±49 ps and 220±41 ps respectively, compared to 276 ps that we considered for bulk BGO. The complex distribution of timing resolutions was accounted for in the reconstruction. We divided the events into three groups based on their CTR and modeled them with different Gaussian TOF kernels. On a NEMA IQ phantom, the heterostructures had better contrast recovery in early iterations. On the other hand, BGO achieved a better contrast to noise ratio (CNR) after the 15th iteration due to the higher sensitivity. The developed simulation and reconstruction methods constitute new tools for evaluating different detector designs with complex time responses. KW - TOF PET KW - Heterostructure KW - Metascintillator KW - Multiple TOF kernels KW - Image Reconstruction Y1 - 2022 U6 - http://dx.doi.org/10.1109/TRPMS.2022.3208615 SN - 2469-7311 SN - 2469-7303 VL - 7 IS - 1 SP - 41 EP - 51 PB - IEEE CY - New York, NY ER - TY - JOUR A1 - Pham, Phu Tinh A1 - Vu, Khoi Duc A1 - Tran, Thanh Ngoc A1 - Staat, Manfred T1 - A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies Y1 - 2010 N1 - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010. SP - 1 EP - 7 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 -