@article{JablonskiPoghossianKeusgenetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Detection of plant virus particles with a capacitive field-effect sensor}, series = {Analytical and Bioanalytical Chemistry}, volume = {413}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer Nature}, address = {Cham}, issn = {1618-2650}, doi = {10.1007/s00216-021-03448-8}, pages = {5669 -- 5678}, year = {2021}, abstract = {Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.}, language = {en} } @inproceedings{TakenagaHerreraWerneretal.2013, author = {Takenaga, Shoko and Herrera, Cony F. and Werner, Frederik and Biselli, Manfred and Schnitzler, Thomas and Sch{\"o}ning, Michael Josef and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten}, title = {Detection of the metabolic activity of cells by differential measurements based on a single light-addressable potentiometric sensor chip}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {63 -- 67}, year = {2013}, language = {en} } @inproceedings{BohrnMuchaWerneretal.2012, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and St{\"u}tz, Evamaria and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Detection of toxic chromium species in water using cellbased sensor systems}, isbn = {978-3-9813484-2-2}, doi = {10.5162/IMCS2012/P2.1.14}, pages = {1364 -- 1367}, year = {2012}, language = {en} } @article{WarmerWagnerSchoeningetal.2015, author = {Warmer, Johannes and Wagner, Patrick and Sch{\"o}ning, Michael Josef and Kaul, Peter}, title = {Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431882}, pages = {1289 -- 1298}, year = {2015}, language = {en} } @article{WagnerKloockSchoening2007, author = {Wagner, Torsten and Kloock, Joachim P. and Sch{\"o}ning, Michael Josef}, title = {Determination of cadmium concentration and pH value in aqueous solutions by means of a handheld light-addressable potentiometric sensor (LAPS) device}, series = {Electrochemical sensor analysis / edited by S. Alegret ...}, journal = {Electrochemical sensor analysis / edited by S. Alegret ...}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-444-53133-9}, pages = {e35 -- e44}, year = {2007}, language = {en} } @article{WernerKrumbeSchumacheretal.2011, author = {Werner, Frederik and Krumbe, Christoph and Schumacher, Katharina and Groebel, Simone and Spelthahn, Heiko and Stellberg, Michael and Wagner, Torsten and Yoshinobu, Tatsuo and Selmer, Thorsten and Keusgen, Michael and Baumann, Marcus and Sch{\"o}ning, Michael Josef}, title = {Determination of the extracellular acidification of Escherichia coli by a light-addressable potentiometric sensor}, series = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, journal = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, publisher = {Wiley}, address = {Weinheim}, isbn = {1862-6319}, pages = {1340 -- 1344}, year = {2011}, language = {en} } @article{DantismTakenagaWagneretal.2016, author = {Dantism, Shahriar and Takenaga, Shoko and Wagner, Patrick and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Determination of the extracellular acidification of Escherichia coli K12 with a multi-​chamber-​based LAPS system}, series = {Physica status solidi (a)}, volume = {213}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300}, doi = {10.1002/pssa.201533043}, pages = {1479 -- 1485}, year = {2016}, abstract = {On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable "down times" during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements.}, language = {en} } @article{SousaSiqueiraVerciketal.2017, author = {Sousa, Marcos A. M. and Siqueira, Jose R. Jr. and Vercik, Andres and Sch{\"o}ning, Michael Josef and Oliveira, Osvaldo N. Jr.}, title = {Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors}, series = {IEEE Sensors Journal}, volume = {17}, journal = {IEEE Sensors Journal}, number = {6}, publisher = {IEEE}, address = {New York}, issn = {1558-1748}, doi = {10.1109/JSEN.2017.2653238}, pages = {1735 -- 1740}, year = {2017}, abstract = {The capacitive electrolyte-insulator-semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte-insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors.}, language = {en} } @article{KueppersSteffenHellmuthetal.2014, author = {K{\"u}ppers, Tobias and Steffen, Victoria and Hellmuth, Hendrik and O'Connell, Timothy and Bongaerts, Johannes and Maurer, Karl-Heinz and Wiechert, Wolfgang}, title = {Developing a new production host from a blueprint: Bacillus pumilus as an industrial enzyme producer}, series = {Microbial cell factories}, volume = {13}, journal = {Microbial cell factories}, publisher = {BioMed Central}, address = {London}, issn = {1475-2859 (E-Journal)}, doi = {10.1186/1475-2859-13-46}, pages = {Article No. 46}, year = {2014}, language = {en} } @article{WagnerWernerMiyamotoetal.2012, author = {Wagner, Torsten and Werner, Frederik and Miyamoto, Ko-Ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Development and characterisation of a compact light-addressable potentiometric sensor (LAPS) based on the digital light processing (DLP) technology for flexible chemical imaging}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2010.12.003}, pages = {34 -- 39}, year = {2012}, abstract = {Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device, which allows fast and flexible generation of light patterns. With the help of these light patterns, the sensor surface of the LAPS device can be addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface.}, language = {en} }