@inproceedings{WernerYoshinobuMiyamotoetal.2014, author = {Werner, Frederik and Yoshinobu, T. and Miyamoto, K. and Sch{\"o}ning, Michael Josef and Wagner, Torsten}, title = {Semiconductor-based sensors for imaging of chemical processes}, series = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, booktitle = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, publisher = {VDE-Verl.}, address = {D{\"u}sseldorf}, organization = {VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, isbn = {978-3-8007-3622-5}, pages = {1 -- 5}, year = {2014}, language = {en} } @article{BronderWuPoghossianetal.2014, author = {Bronder, Thomas and Wu, Chunsheng and Poghossian, Arshak and Werner, Frederik and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.647}, pages = {755 -- 758}, year = {2014}, abstract = {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).}, language = {en} } @article{BohrnMuchaWerneretal.2013, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and Trattner, Barbara and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and St{\"u}tz, Evamaria and Schmitt-Landsiedel, Doris and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment}, series = {Sensors and actuators. B: Chemical}, volume = {Vol. 182}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, pages = {58 -- 65}, year = {2013}, language = {en} } @inproceedings{WuPoghossianWerneretal.2013, author = {Wu, Chunsheng and Poghossian, Arshak and Werner, Frederik and Bronder, Thomas and B{\"a}cker, Matthias and Wang, Ping and Sch{\"o}ning, Michael Josef}, title = {An application of a scanning light-addressable potentiometric sensor for label-free DNA detection}, 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 = {164 -- 168}, year = {2013}, language = {en} } @article{WernerTakenagaTakietal.2013, author = {Werner, Frederik and Takenaga, Shoko and Taki, Hidenori and Sawada, Kazuaki and Sch{\"o}ning, Michael Josef}, title = {Comparison of label-free ACh-imaging sensors based on CCD and LAPS}, series = {Sensors and Actuators B: Chemical (2012)}, volume = {177}, journal = {Sensors and Actuators B: Chemical (2012)}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0925-4005}, pages = {745 -- 752}, year = {2013}, abstract = {Semiconductor-based chemical imaging sensors, like the light-addressable potentiometric sensor (LAPS) or the pH-imaging sensor based on a charge-coupled device (CCD), are becoming a powerful tool for label-free imaging of biological phenomena. We have proposed a polyion-based enzymatic membrane to develop an acetylcholine (ACh) imaging sensor for neural cell-activity observations. In this study, a CCD-type ACh-imaging sensor and a LAPS-type ACh-imaging sensor were fabricated and the prospect of both sensors was clarified by making a comparison of their basic characteristics.}, language = {en} } @article{WernerWagnerYoshinobuetal.2013, author = {Werner, Frederik and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Frequency behaviour of light-addressable potentiometric sensors}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200929}, pages = {884 -- 891}, year = {2013}, abstract = {Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.}, language = {en} } @article{WernerWagnerMiyamotoetal.2012, author = {Werner, Frederik and Wagner, Torsten and Miyamoto, Ko-ichiro and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {High speed and high resolution chemical imaging based on a new type of OLED-LAPS set-up}, series = {Sensors and Actuators B: Chemical}, volume = {175}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.12.102}, pages = {118 -- 122}, year = {2012}, abstract = {Light-addressable potentiometric sensors (LAPS) are field-effect-based sensors. A modulated light source is used to define the particular measurement spot to perform spatially resolved measurements of chemical species and to generate chemical images. In this work, an organic-LED (OLED) display has been chosen as a light source. This allows high measurement resolution and miniaturisation of the system. A new developed driving method for the OLED display optimised for LAPS-based measurements is demonstrated. The new method enables to define modulation frequencies between 1 kHz and 16 kHz and hence, reduces the measurement time of a chemical image by a factor of 40 compared to the traditional addressing of an OLED display.}, 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} } @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} } @inproceedings{TakenagaWernerSawadaetal.2012, author = {Takenaga, Shoko and Werner, Frederik and Sawada, Kazuaki and Sch{\"o}ning, Michael Josef}, title = {Comparison of label-free ACh image sensors based on CCD and LAPS}, isbn = {978-3-9813484-2-2}, doi = {10.5162/IMCS2012/4.2.6}, pages = {356 -- 359}, year = {2012}, language = {en} }