@incollection{PieronekKleefeld2019, author = {Pieronek, Lukas and Kleefeld, Andreas}, title = {The Method of Fundamental Solutions for Computing Interior Transmission Eigenvalues of Inhomogeneous Media}, series = {Integral Methods in Science and Engineering: Analytic Treatment and Numerical Approximations}, booktitle = {Integral Methods in Science and Engineering: Analytic Treatment and Numerical Approximations}, editor = {Constanda, Christian and Harris, Paul}, publisher = {Birkh{\"a}user}, address = {Cham}, isbn = {978-3-030-16077-7}, doi = {10.1007/978-3-030-16077-7_28}, pages = {353 -- 365}, year = {2019}, abstract = {The method of fundamental solutions is applied to the approximate computation of interior transmission eigenvalues for a special class of inhomogeneous media in two dimensions. We give a short approximation analysis accompanied with numerical results that clearly prove practical convenience of our alternative approach.}, language = {en} } @article{PieronekKleefeld2024, author = {Pieronek, Lukas and Kleefeld, Andreas}, title = {On trajectories of complex-valued interior transmission eigenvalues}, series = {Inverse problems and imaging : IPI}, volume = {18}, journal = {Inverse problems and imaging : IPI}, number = {2}, publisher = {AIMS}, address = {Springfield, Mo}, issn = {1930-8337 (Print)}, doi = {10.3934/ipi.2023041}, pages = {480 -- 516}, year = {2024}, abstract = {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.}, language = {en} } @inproceedings{PijanowskaRemiszewska2006, author = {Pijanowska, Dorota G. and Remiszewska, Elzbieta}, title = {pH-based detection of phenylalnine by potentiometric and colorimetric methods}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1536}, year = {2006}, abstract = {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.}, subject = {Biosensor}, language = {en} } @inproceedings{PijanowskaRemiszewskaPederzollietal.2006, author = {Pijanowska, Dorota G. and Remiszewska, Elzbieta and Pederzolli, Cecilia and Lunelli, Lorenzo and Vendano, Michele and Canteri, Roberto and Dudzinski, Konrad and Kruk, Jerzy and Torbicz, Wladyslaw}, title = {Surface modification for microreactor fabrication}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1480}, year = {2006}, abstract = {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.}, subject = {Biosensor}, language = {en} } @article{PilasIkenSelmeretal.2015, author = {Pilas, Johanna and Iken, Heiko and Selmer, Thorsten and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Development of a multi-parameter sensor chip for the simultaneous detection of organic compounds in biogas processes}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431894}, pages = {1306 -- 1312}, year = {2015}, abstract = {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.}, language = {en} } @article{PilasMarianoKeusgenetal.2015, author = {Pilas, Johanna and Mariano, K. and Keusgen, M. and Selmer, Thorsten and Sch{\"o}ning, Michael Josef}, title = {Optimization of an Enzyme-based Multi-parameter Biosensor for Monitoring Biogas Processes}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.702}, pages = {532 -- 535}, year = {2015}, language = {en} } @article{PilasSelmerKeusgenetal.2019, author = {Pilas, Johanna and Selmer, Thorsten and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Screen-printed carbon electrodes modified with graphene oxide for the design of a reagent-free NAD+-dependent biosensor array}, series = {Analytical Chemistry}, volume = {91}, journal = {Analytical Chemistry}, number = {23}, publisher = {ACS Publications}, address = {Washington}, doi = {10.1021/acs.analchem.9b04481}, pages = {15293 -- 15299}, year = {2019}, language = {en} } @article{PilasYaziciSelmeretal.2018, author = {Pilas, Johanna and Yazici, Y. and Selmer, Thorsten and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Application of a portable multi-analyte biosensor for organic acid determination in silage}, series = {Sensors}, volume = {18}, journal = {Sensors}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s18051470}, pages = {12 Seiten}, year = {2018}, abstract = {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.}, language = {en} } @article{PilasYaziciSelmeretal.2017, author = {Pilas, Johanna and Yazici, Yasemen and Selmer, Thorsten and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Optimization of an amperometric biosensor array for simultaneous measurement of ethanol, formate, d- and l-lactate}, series = {Electrochimica Acta}, volume = {251}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-4686}, doi = {10.1016/j.electacta.2017.07.119}, pages = {256 -- 262}, year = {2017}, abstract = {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.}, language = {en} } @article{PitaKraemerZouhetal.2008, author = {Pita, Marcos and Kr{\"a}mer, Melina and Zouh, Jian and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Fernandez, Victor M. and Katz, Evgeny}, title = {Optoelectronic Properties of Nanostructured Ensembles Controlled by Biomolecular Logic Systems}, series = {ACS Nano. 10 (2008), H. 2}, journal = {ACS Nano. 10 (2008), H. 2}, isbn = {1936-086X}, pages = {2160 -- 2166}, year = {2008}, language = {en} } @inproceedings{PlatenPoghossianSchoening2006, author = {Platen, J. and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Pr{\"a}paration von selbstjustierenden Nanostrukturen mittels Schichtausdehnungstechnik}, series = {Sensoren und Mess-Systeme 2006 : Vortr{\"a}ge der 13. ITG/GMA-Fachtagung vom 13. bis 14.3.2006 in Freiburg/Breisgau}, booktitle = {Sensoren und Mess-Systeme 2006 : Vortr{\"a}ge der 13. ITG/GMA-Fachtagung vom 13. bis 14.3.2006 in Freiburg/Breisgau}, publisher = {VDE Verl.}, address = {Berlin}, isbn = {3-8007-2939-3}, pages = {277 -- 280}, year = {2006}, language = {de} } @inproceedings{PlatenPoghossianSchoening2006, author = {Platen, Johannes and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Microstructured Nanostructures - nanostructuring by means of conventional photolithography and layer-expansion technique}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1477}, year = {2006}, abstract = {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.}, subject = {Biosensor}, language = {en} } @article{PoghossianAbouzarAmbergeretal.2007, author = {Poghossian, Arshak and Abouzar, Maryam H. and Amberger, F. and Mayer, D. and Han, Y. and Ingebrandt, S. and Offenh{\"a}usser, A. and Sch{\"o}ning, Michael Josef}, title = {Field-effect sensors with charged macromolecules: Characterisation by capacitance-voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods}, series = {Biosensors and Bioelectronics. 22 (2007), H. 9-10}, journal = {Biosensors and Bioelectronics. 22 (2007), H. 9-10}, isbn = {0956-5663}, pages = {2100 -- 2107}, year = {2007}, language = {en} } @article{PoghossianAbouzarChristiaensetal.2007, author = {Poghossian, Arshak and Abouzar, Maryam H. and Christiaens, P. and Williams, O. A. and Haenen, K. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Nanocrystalline diamond-based field-effect (bio-)chemical sensor}, series = {8. Dresdner Sensor-Symposium : Sensoren f{\"u}r Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme f{\"u}r die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung f{\"u}r die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)}, journal = {8. Dresdner Sensor-Symposium : Sensoren f{\"u}r Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme f{\"u}r die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung f{\"u}r die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)}, publisher = {TUDpress, Verl. der Wissenschaften}, address = {Dresden}, isbn = {978-3-940046-45-1}, pages = {191 -- 194}, year = {2007}, language = {en} } @article{PoghossianAbouzarChristiaensetal.2008, author = {Poghossian, Arshak and Abouzar, Maryam H. and Christiaens, P. and Williams, O. A. and Haenen, K. and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Sensing charged macromolecules with nanocrystalline diamond-based field-effect capacitive sensors}, series = {Journal of Contemporary Physics. 43 (2008), H. 2}, journal = {Journal of Contemporary Physics. 43 (2008), H. 2}, isbn = {1934-9378}, pages = {77 -- 81}, year = {2008}, language = {en} } @article{PoghossianAbouzarRazavietal.2009, author = {Poghossian, Arshak and Abouzar, Maryam H. and Razavi, A. and B{\"a}cker, Matthias and Bijnens, N. and Williams, O. A. and Haenen, K. and Moritz, W. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Nanocrystalline-diamond thin films with high pH and penicillin sensitivity prepared on a capacitive Si-SiO2 structure}, series = {Electrochimica Acta. 54 (2009), H. 25}, journal = {Electrochimica Acta. 54 (2009), H. 25}, isbn = {0013-4686}, pages = {5981 -- 5985}, year = {2009}, language = {en} } @article{PoghossianAbouzarSakkarietal.2006, author = {Poghossian, Arshak and Abouzar, Maryam H. and Sakkari, M. and Kassab, T. and Han, Y. and Ingebrandt, S. and Offenh{\"a}usser, A. and Sch{\"o}ning, Michael Josef}, title = {Field-effect sensors for monitoring the layer-by-layer adsorption of charged macromolecules}, series = {Sensors and Actuators B: Chemical. 118 (2006), H. 1-2}, journal = {Sensors and Actuators B: Chemical. 118 (2006), H. 1-2}, isbn = {0925-4005}, pages = {163 -- 170}, year = {2006}, language = {en} } @article{PoghossianAbouzarSchoening2008, author = {Poghossian, Arshak and Abouzar, Maryam H. and Sch{\"o}ning, Michael Josef}, title = {Capacitance-voltage and impedance characteristics of field-effect EIS sensors functionalised with polyelectrolyte multilayers}, series = {IRBM. 29 (2008), H. 2-3}, journal = {IRBM. 29 (2008), H. 2-3}, isbn = {1959-0318}, pages = {149 -- 154}, year = {2008}, language = {en} } @inproceedings{PoghossianAbouzarSchoening2012, author = {Poghossian, Arshak and Abouzar, Maryam H. and Sch{\"o}ning, Michael Josef}, title = {(Bio-­)chemical sensor array based on nanoplate SOI capacitors}, series = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, booktitle = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, editor = {Abdelghani, Adnane and Sch{\"o}ning, Michael Josef}, pages = {31 -- 31}, year = {2012}, language = {en} } @article{PoghossianBaadeEmonsetal.2001, author = {Poghossian, Arshak and Baade, A. and Emons, H. and Sch{\"o}ning, Michael Josef}, title = {Application of ISFET for pH measurements in rain droplets}, series = {Sensors and Actuators B. 76 (2001), H. 1-3}, journal = {Sensors and Actuators B. 76 (2001), H. 1-3}, isbn = {0925-4005}, pages = {634 -- 638}, year = {2001}, language = {en} }