@inproceedings{WagnerYoshinobuSchoening2008,
  author    = {Wagner, Torsten and Yoshinobu, T. and Sch{\"o}ning, Michael Josef},
  title     = {Light-addressable potentiometric sensor as semiconductor-based sensor platform for (bio-) chemical sensing},
  series = {Armenian Journal of Physics},
  booktitle = {Armenian Journal of Physics},
  issn      = {1829-1171},
  pages     = {99 -- 103},
  year      = {2008},
  language  = {en}
}
@article{WagnerSchoening2007,
  author    = {Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Light-addressable potentiometric sensors (LAPS): recent trends and applications},
  series = {Electrochemical sensor analysis / edited by S. Alegret ...},
  journal   = {Electrochemical sensor analysis / edited by S. Alegret ...},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-444-53053-0},
  pages     = {87 -- 128},
  year      = {2007},
  language  = {en}
}
@article{WagnerShigiaharaMiyamotoetal.2012,
  author    = {Wagner, Torsten and Shigiahara, N. and Miyamoto, K. and Suzurikawa, J. and Finger, F. and Sch{\"o}ning, Michael Josef and Yoshinobu, T.},
  title     = {Light-addressable Potentiometric Sensors and Light-addressable Electrodes as a Combined Sensor-and-manipulator Microsystem with High Flexibility},
  series = {Procedia Engineering},
  journal   = {Procedia Engineering},
  number    = {47},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2012.09.290},
  pages     = {890 -- 893},
  year      = {2012},
  abstract  = {This work describes the novel combination of the light-addressable electrode (LAE) and the light-addressable potentiometric sensor (LAPS) into a microsystem set-up. Both the LAE as well as the LAPS shares the principle of addressing the active spot by means of a light beam. This enables both systems to manipulate resp. to detect an analyte with a high spatial resolution. Hence, combining both principles into a single set-up enables the active stimulation e.g., by means of electrolysis and a simultaneous observation e.g., the response of an entrapped biological cell by detection of extracellular pH changes. The work will describe the principles of both technologies and the necessary steps to integrate them into a single set-up. Furthermore, examples of application and operation of such systems will be presented.},
  language  = {en}
}
@incollection{SchoeningWagnerPoghossianetal.2018,
  author    = {Sch{\"o}ning, Michael Josef and Wagner, Torsten and Poghossian, Arshak and Miyamoto, K.I. and Werner, C.F. and Krause, S. and Yoshinobu, T.},
  title     = {Light-addressable potentiometric sensors for (bio-)chemical sensing and imaging},
  series = {Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7},
  booktitle = {Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {9780128097397},
  pages     = {295 -- 308},
  year      = {2018},
  language  = {en}
}
@article{YoshinobuMiyamotoWerneretal.2017,
  author    = {Yoshinobu, Tatsuo and Miyamoto, Ko-ichiro and Werner, Frederik and Poghossian, Arshak and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Light-addressable potentiometric sensors for quantitative spatial imaging of chemical species},
  series = {Annual Review of Analytical Chemistry},
  volume    = {10},
  journal   = {Annual Review of Analytical Chemistry},
  publisher = {Annual Reviews},
  address   = {Palo Alto, Calif.},
  issn      = {1936-1327},
  doi       = {10.1146/annurev-anchem-061516-045158},
  pages     = {225 -- 246},
  year      = {2017},
  abstract  = {A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed.},
  language  = {en}
}
@article{BreuerRaueKirschbaumetal.2015,
  author    = {Breuer, Lars and Raue, Markus and Kirschbaum, M. and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, R. and Wagner, Torsten},
  title     = {Light-controllable polymeric material based on temperature-sensitive hydrogels with incorporated graphene oxide},
  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.201431944},
  pages     = {1368 -- 1374},
  year      = {2015},
  abstract  = {Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel films with incorporated graphene oxide (GO) were developed and tested as light-stimulated actuators. GO dispersions were synthesized via Hummers method and characterized toward their optical properties and photothermal energy conversion. The hydrogels were prepared by means of photopolymerization. In addition, the influence of GO within the hydrogel network on the lower critical solution temperature (LCST) was investigated by differential scanning calorimetry (DSC). The optical absorbance and the response to illumination were determined as a function of GO concentration for thin hydrogel films. A proof of principle for the stimulation with light was performed.},
  language  = {en}
}
@inproceedings{BreuerRaueMangetal.2015,
  author    = {Breuer, Lars and Raue, Markus and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, Ronald and Wagner, Torsten},
  title     = {Light-stimulated hydrogel actuators with incorporated graphene oxide for microfluidic applications},
  series = {12. Dresdner Sensor-Symposium 2015},
  booktitle = {12. Dresdner Sensor-Symposium 2015},
  doi       = {10.5162/12dss2015/P5.8},
  pages     = {206 -- 209},
  year      = {2015},
  language  = {en}
}
@inproceedings{BreuerGuthmannSchoeningetal.2017,
  author    = {Breuer, Lars and Guthmann, Eric and Sch{\"o}ning, Michael Josef and Thoelen, Ronald and Wagner, Torsten},
  title     = {Light-Stimulated Hydrogels with Incorporated Graphene Oxide as Actuator Material for Flow Control in Microfluidic Applications},
  series = {Proceedings Eurosensors 2017 Conference, Paris, France, 3-6 September 2017},
  booktitle = {Proceedings Eurosensors 2017 Conference, Paris, France, 3-6 September 2017},
  doi       = {10.3390/proceedings1040524},
  pages     = {1 -- 4},
  year      = {2017},
  language  = {en}
}
@article{WagnerMiyamotoShigiharaetal.2011,
  author    = {Wagner, Torsten and Miyamoto, Ko-ichiro and Shigihara, Noriko and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Microfluidic systems with free definable sensor spots by an integrated light-addressable potentiometric sensor},
  series = {Procedia Engineering. 25 (2011)},
  journal   = {Procedia Engineering. 25 (2011)},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {1877-7058},
  pages     = {791 -- 794},
  year      = {2011},
  language  = {en}
}
@inproceedings{YoshinobuMiyamotoWagneretal.2012,
  author    = {Yoshinobu, Tatsuo and Miyamoto, Ko-Ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Miniaturized and high-speed chemical imaging systems},
  series = {Nano-Biomedical Engineering 2012. Proceedings of the Tohoku University Global Centre of Excellence Programme, Sakura Hall, Tohoku University, Sendai Japan, 5 - 6 March 2012},
  booktitle = {Nano-Biomedical Engineering 2012. Proceedings of the Tohoku University Global Centre of Excellence Programme, Sakura Hall, Tohoku University, Sendai Japan, 5 - 6 March 2012},
  editor    = {Yamaguchi, Takami},
  publisher = {World Scientific},
  address   = {Singapur},
  doi       = {10.1142/9781848169067_0045},
  pages     = {386 -- 395},
  year      = {2012},
  language  = {en}
}
@article{MiyamotoKanekoMatsuoetal.2010,
  author    = {Miyamoto, Ko-ichiro and Kaneko, Kazumi and Matsuo, Akira and Wagner, Torsten and Kanoh, Shin`ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Miniaturized chemical imaging sensor system using an OLED display panel},
  series = {Procedia Engineering. 5 (2010)},
  journal   = {Procedia Engineering. 5 (2010)},
  isbn      = {1877-7058},
  pages     = {516 -- 519},
  year      = {2010},
  language  = {en}
}
@article{MiyamotoKanekoMatsuoetal.2012,
  author    = {Miyamoto, Ko-ichiro and Kaneko, Kazumi and Matsuo, Akira and Wagner, Torsten and Kanoh, Shin{\´i}chiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Miniaturized chemical imaging sensor system using an OLED display panel},
  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.2011.02.029},
  pages     = {82 -- 87},
  year      = {2012},
  abstract  = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the current-voltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.},
  language  = {en}
}
@article{MiyamotoWagnerSchoeningetal.2011,
  author    = {Miyamoto, K. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, T.},
  title     = {Multi-well structure for cell culture on the chemical imaging sensor},
  publisher = {IEEE},
  address   = {New York},
  pages     = {2130 -- 2132},
  year      = {2011},
  language  = {en}
}
@article{ChristiaensAbouzarPoghossianetal.2007,
  author    = {Christiaens, P. and Abouzar, Maryam H. and Poghossian, Arshak and Wagner, Torsten and Bijnens, N. and Williams, O. A. and Daenen, M. and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, P.},
  title     = {Nanocrystalline diamond-based field-effect capacitive pH sensor},
  series = {Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.)},
  journal   = {Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.)},
  publisher = {IEEE},
  address   = {Piscataway},
  isbn      = {1-4244-0841-5},
  pages     = {1891 -- 1894},
  year      = {2007},
  language  = {en}
}
@article{WagnerMiyamotoSchoeningetal.2010,
  author    = {Wagner, Torsten and Miyamoto, Ko-ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Novel combination of digital light processing (DLP) and light-addressable potentiometric sensors (LAPS) for flexible chemical imaging},
  series = {Procedia Engineering. 5 (2010)},
  journal   = {Procedia Engineering. 5 (2010)},
  isbn      = {1877-7058},
  pages     = {520 -- 523},
  year      = {2010},
  language  = {en}
}
@article{GuoSekiMiyamotoetal.2014,
  author    = {Guo, Yuanyuan and Seki, Kosuke and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Novel photoexcitation method for light-addressable potentiometric sensor with higher spatial resolution},
  series = {Applied physics express : APEX},
  volume    = {7},
  journal   = {Applied physics express : APEX},
  number    = {6},
  publisher = {IOP},
  address   = {Bristol},
  issn      = {1882-0786 (E-Journa); 1882-0778 (Print)},
  doi       = {10.7567/APEX.7.067301},
  pages     = {067301-4},
  year      = {2014},
  abstract  = {A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) is proposed to achieve a higher spatial resolution of chemical images. The proposed method employs a combined light source that consists of a modulated light probe, which generates the alternating photocurrent signal, and a ring of constant illumination surrounding it. The constant illumination generates a sheath of carriers with increased concentration which suppresses the spread of photocarriers by enhanced recombination. A device simulation was carried out to verify the effect of constant illumination on the spatial resolution, which demonstrated that a higher spatial resolution can be obtained.},
  language  = {en}
}
@article{WernerGroebelKrumbeetal.2012,
  author    = {Werner, Frederik and Groebel, Simone and Krumbe, Christoph and Wagner, Torsten and Selmer, Thorsten and Yoshinobu, Tatsuo and Baumann, Marcus and Sch{\"o}ning, Michael Josef},
  title     = {Nutrient concentration-sensitive microorganism-based biosensor},
  series = {Physica Status Solidi (a)},
  volume    = {209},
  journal   = {Physica Status Solidi (a)},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201100801},
  pages     = {900 -- 904},
  year      = {2012},
  language  = {en}
}
@article{DantismRoehlenWagneretal.2018,
  author    = {Dantism, Shahriar and R{\"o}hlen, Desiree and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Optimization of Cell-Based Multi-Chamber LAPS Measurements Utilizing FPGA-Controlled Laser-Diode Modules},
  series = {physica status solidi a : applications and materials sciences},
  volume    = {215},
  journal   = {physica status solidi a : applications and materials sciences},
  number    = {15},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201800058},
  pages     = {Article number 1800058},
  year      = {2018},
  abstract  = {A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric device, which detects concentration changes of an analyte solution on the sensor surface in a spatially resolved way. It uses a light source to generate electron-hole pairs inside the semiconductor, which are separated in the depletion region due to an applied bias voltage across the sensor structure and hence, a surface-potential-dependent photocurrent can be read out. However, depending on the beam angle of the light source, scattering effects can occur, which influence the recorded signal in LAPS-based differential measurements. To solve this problem, a novel illumination unit based on a field programmable gate array (FPGA) consisting of 16 small-sized tunable infrared laser-diode modules (LDMs) is developed. Due to the improved focus of the LDMs with a beam angle of only 2 mrad, undesirable scattering effects are minimized. Escherichia coli (E. coli) K12 bacteria are used as a test microorganism to study the extracellular acidification on the sensor surface. Furthermore, a salt bridge chamber is built up and integrated with the LAPS system enabling multi-chamber differential measurements with a single Ag/AgCl reference electrode.},
  language  = {en}
}
@article{ChristiaensAbouzarPoghossianetal.2007,
  author    = {Christiaens, P. and Abouzar, Maryam H. and Poghossian, Arshak and Wagner, Torsten and Bijnens, N. and Williams, O. A. and Daenen, M. and Haenen, K. and Douth{\´e}ret, O. and Haen, J. d´ and Mekhalif, Z. and Sch{\"o}ning, Michael Josef and Wagner, P.},
  title     = {pH sensitivity of nanocrystalline diamond films},
  series = {Physica status solidi (A). 204 (2007), H. 9},
  journal   = {Physica status solidi (A). 204 (2007), H. 9},
  isbn      = {0031-8965},
  pages     = {2925 -- 2930},
  year      = {2007},
  language  = {en}
}
@article{MiyamotoWagnerYoshinobuetal.2011,
  author    = {Miyamoto, Ko-ichiro and Wagner, Torsten and Yoshinobu, Tatsuo and Kanoh, Shin`ichiro and Sch{\"o}ning, Michael Josef},
  title     = {Phase-mode LAPS and its application to chemical imaging},
  series = {Sensors and Actuators B: Chemical. 154 (2011), H. 1},
  journal   = {Sensors and Actuators B: Chemical. 154 (2011), H. 1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {1873-3077},
  pages     = {28 -- 32},
  year      = {2011},
  language  = {en}
}