@article{VahidpourGuthmanArreolaetal.2022, author = {Vahidpour, Farnoosh and Guthman, Eric and Arreola, Julia and Alghazali, Yousef H. M. and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Assessment of Various Process Parameters for Optimized Sterilization Conditions Using a Multi-Sensing Platform}, series = {Foods}, volume = {11}, journal = {Foods}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2304-8158}, doi = {10.3390/foods11050660}, pages = {Artikel 660}, year = {2022}, abstract = {In this study, an online multi-sensing platform was engineered to simultaneously evaluate various process parameters of food package sterilization using gaseous hydrogen peroxide (H₂O₂). The platform enabled the validation of critical aseptic parameters. In parallel, one series of microbiological count reduction tests was performed using highly resistant spores of B. atrophaeus DSM 675 to act as the reference method for sterility validation. By means of the multi-sensing platform together with microbiological tests, we examined sterilization process parameters to define the most effective conditions with regards to the highest spore kill rate necessary for aseptic packaging. As these parameters are mutually associated, a correlation between different factors was elaborated. The resulting correlation indicated the need for specific conditions regarding the applied H₂O₂ gas temperature, the gas flow and concentration, the relative humidity and the exposure time. Finally, the novel multi-sensing platform together with the mobile electronic readout setup allowed for the online and on-site monitoring of the sterilization process, selecting the best conditions for sterility and, at the same time, reducing the use of the time-consuming and costly microbiological tests that are currently used in the food package industry.}, language = {en} } @article{VahidpourAlghazaliAkcaetal.2022, author = {Vahidpour, Farnoosh and Alghazali, Yousef and Akca, Sevilay and Hommes, Gregor and Sch{\"o}ning, Michael Josef}, title = {An Enzyme-Based Interdigitated Electrode-Type Biosensor for Detecting Low Concentrations of H₂O₂ Vapor/Aerosol}, series = {Chemosensors}, volume = {10}, journal = {Chemosensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2227-9040}, doi = {10.3390/chemosensors10060202}, pages = {Arikel 202}, year = {2022}, abstract = {This work introduces a novel method for the detection of H₂O₂ vapor/aerosol of low concentrations, which is mainly applied in the sterilization of equipment in medical industry. Interdigitated electrode (IDE) structures have been fabricated by means of microfabrication techniques. A differential setup of IDEs was prepared, containing an active sensor element (active IDE) and a passive sensor element (passive IDE), where the former was immobilized with an enzymatic membrane of horseradish peroxidase that is selective towards H₂O₂. Changes in the IDEs' capacitance values (active sensor element versus passive sensor element) under H₂O₂ vapor/aerosol atmosphere proved the detection in the concentration range up to 630 ppm with a fast response time (<60 s). The influence of relative humidity was also tested with regard to the sensor signal, showing no cross-sensitivity. The repeatability assessment of the IDE biosensors confirmed their stable capacitive signal in eight subsequent cycles of exposure to H₂O₂ vapor/aerosol. Room-temperature detection of H₂O₂ vapor/aerosol with such miniaturized biosensors will allow a future three-dimensional, flexible mapping of aseptic chambers and help to evaluate sterilization assurance in medical industry.}, language = {en} } @article{TurekKettererClassenetal.2007, author = {Turek, Monika and Ketterer, Lothar and Claßen, Melanie and Berndt, Heinz and Elbers, Gereon and Kr{\"u}ger, Peter and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Development and Electrochemical Investigations of an EIS-(Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection}, series = {Sensors}, volume = {7}, journal = {Sensors}, number = {8}, isbn = {1424-8220}, pages = {1415 -- 1426}, year = {2007}, language = {en} } @article{TurekHeidenGuoetal.2010, author = {Turek, Monik and Heiden, Wolfgang and Guo, Sharon and Riesen, Alfred and Schubert, J{\"u}rgen and Zander, Willi and Kr{\"u}ger, Peter and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Simultaneous detection of cyanide and heavy metals for environmental analysis by means of µISEs}, series = {Physica Status Solidi (A). 207 (2010), H. 4}, journal = {Physica Status Solidi (A). 207 (2010), H. 4}, isbn = {1862-6300}, pages = {817 -- 823}, year = {2010}, language = {en} } @article{TurekKeusgenPoghossianetal.2008, author = {Turek, M. and Keusgen, M. and Poghossian, Arshak and Mulchandani, A. and Wang, J. and Sch{\"o}ning, Michael Josef}, title = {Enzyme-modified electrolyte-insulator-semiconductor sensors}, series = {Journal of Contemporary Physics. 43 (2008), H. 2}, journal = {Journal of Contemporary Physics. 43 (2008), H. 2}, isbn = {1934-9378}, pages = {82 -- 85}, year = {2008}, language = {en} } @article{TillmannFoerster2000, author = {Tillmann, K. and F{\"o}rster, Arnold}, title = {Critical dimensions for the formation of interfacial misfit dislocations of In0.6Ga0.4As islands on GaAs(001)}, series = {Thin Solid Films. 368 (2000), H. 1}, journal = {Thin Solid Films. 368 (2000), H. 1}, isbn = {0040-6090}, pages = {93 -- 104}, year = {2000}, language = {en} } @article{TakenagaSchneiderErbayetal.2015, author = {Takenaga, Shoko and Schneider, Benno and Erbay, E. and Biselli, Manfred and Schnitzler, Thomas and Sch{\"o}ning, Michael Josef and Wagner, Torsten}, title = {Fabrication of biocompatible lab-on-chip devices for biomedical applications by means of a 3D-printing process}, 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.201532053}, pages = {1347 -- 1352}, year = {2015}, abstract = {A new microfluidic assembly method for semiconductor-based biosensors using 3D-printing technologies was proposed for a rapid and cost-efficient design of new sensor systems. The microfluidic unit is designed and printed by a 3D-printer in just a few hours and assembled on a light-addressable potentiometric sensor (LAPS) chip using a photo resin. The cell growth curves obtained from culturing cells within microfluidics-based LAPS systems were compared with cell growth curves in cell culture flasks to examine biocompatibility of the 3D-printed chips. Furthermore, an optimal cell culturing within microfluidics-based LAPS chips was achieved by adjusting the fetal calf serum concentrations of the cell culture medium, an important factor for the cell proliferation.}, language = {en} } @article{TakenagaBiselliSchnitzleretal.2014, author = {Takenaga, Shoko and Biselli, Manfred and Schnitzler, Thomas and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis-Menten-like kinetics for cell culturing}, series = {Physica status solidi A : Applications and materials science}, volume = {211}, journal = {Physica status solidi A : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330464}, pages = {1410 -- 1415}, year = {2014}, abstract = {The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17-200 mM) follows a Michaelis-Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.}, language = {en} } @article{StockMalindretosIndlekoferetal.2001, author = {Stock, J. and Malindretos, J. and Indlekofer, K.M. and P{\"o}ttgens, Michael and F{\"o}rster, Arnold and L{\"u}th, Hans}, title = {A Vertical Resonant Tunneling Transistor for Application in Digital Logic Circuits}, series = {IEEE Transactions on Electron Devices (T-ED). 48 (2001), H. 6}, journal = {IEEE Transactions on Electron Devices (T-ED). 48 (2001), H. 6}, isbn = {0018-9383}, pages = {1028 -- 1032}, year = {2001}, language = {en} } @article{SrnanekGeurtsLentzeetal.2004, author = {Srnanek, R. and Geurts, J. and Lentze, M. and Irmer, G. and Donoval, D. and Brdecka, P. and Kordos, P. and F{\"o}rster, Arnold and Sciana, B. and Radziewicz, D. and Tlaczala, M.}, title = {Study of d-doped GaAs layers by micro-Raman spectroscopy on bevelled samples}, series = {Applied surface science . 230 (2004), H. 1 -4}, journal = {Applied surface science . 230 (2004), H. 1 -4}, isbn = {0169-4332}, pages = {379 -- 385}, year = {2004}, language = {en} }