@incollection{YoshinobuKrauseMiyamotoetal.2018,
  author    = {Yoshinobu, Tatsuo and Krause, Steffi and Miyamoto, Ko-ichiro and Werner, Frederik and Poghossian, Arshak and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {(Bio-)chemical Sensing and Imaging by LAPS and SPIM},
  series = {Label-free biosensing: advanced materials, devices and applications},
  booktitle = {Label-free biosensing: advanced materials, devices and applications},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-75219-8},
  pages     = {103 -- 132},
  year      = {2018},
  abstract  = {The light-addressable potentiometric sensor (LAPS) and scanning photo-induced impedance microscopy (SPIM) are two closely related methods to visualise the distributions of chemical species and impedance, respectively, at the interface between the sensing surface and the sample solution. They both have the same field-effect structure based on a semiconductor, which allows spatially resolved and label-free measurement of chemical species and impedance in the form of a photocurrent signal generated by a scanning light beam. In this article, the principles and various operation modes of LAPS and SPIM, functionalisation of the sensing surface for measuring various species, LAPS-based chemical imaging and high-resolution sensors based on silicon-on-sapphire substrates are described and discussed, focusing on their technical details and prospective applications.},
  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}
}
@article{WagnerWernerMiyamotoetal.2009,
  author    = {Wagner, Torsten and Werner, Frederik and Miyamoto, K. and Sch{\"o}ning, Michael Josef and Yoshinobu, T.},
  title     = {A high-density multi-point LAPS set-up using a VCSEL array and FPGA control},
  series = {Procedia Chemistry. 1 (2009), H. 1},
  journal   = {Procedia Chemistry. 1 (2009), H. 1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {1876-6196},
  pages     = {1483 -- 1486},
  year      = {2009},
  language  = {en}
}
@article{WagnerWernerMiyamotoetal.2011,
  author    = {Wagner, Torsten and Werner, Frederik and Miyamoto, Ko-Ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {A high-density multi-point LAPS set-up using a VCSEL array and FPGA control},
  series = {Sensors and Actuators B: Chemical. 154 (2011), H. 2},
  journal   = {Sensors and Actuators B: Chemical. 154 (2011), H. 2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {1873-3077},
  pages     = {124 -- 128},
  year      = {2011},
  language  = {en}
}
@article{MiyamotoHayashiSakamotoetal.2017,
  author    = {Miyamoto, Ko-ichiro and Hayashi, Kosuke and Sakamoto, Azuma and Werner, Frederik and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {A high-Q resonance-mode measurement of EIS capacitive sensor by elimination of series resistance},
  series = {Sensor and Actuators B: Chemical},
  volume    = {248},
  journal   = {Sensor and Actuators B: Chemical},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0925-4005},
  doi       = {10.1016/j.snb.2017.03.002},
  pages     = {1006 -- 1010},
  year      = {2017},
  abstract  = {An EIS capacitive sensor is a semiconductor-based potentiometric sensor, which is sensitive to the ion concentration or pH value of the solution in contact with the sensing surface. To detect a small change in the ion concentration or pH, a small capacitance change must be detected. Recently, a resonance-mode measurement was proposed, in which an inductor was connected to the EIS capacitive sensor and the resonant frequency was correlated with the pH value. In this study, the Q factor of the resonant circuit was enhanced by canceling the internal resistance of the reference electrode and the internal resistance of the inductor coil with the help of a bypass capacitor and a negative impedance converter, respectively. 1\% variation of the signal in the developed system corresponded to a pH change of 3.93 mpH, which was about 1/12 of the conventional method, suggesting a better performance in detection of a small pH change.},
  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{WernerGroebelSchuhmacheretal.2009,
  author    = {Werner, Frederik and Groebel, Simone and Schuhmacher, K. and Spelthahn, Heiko and Wagner, Torsten and Selmer, Thorsten and Baumann, Marcus and Sch{\"o}ning, Michael Josef},
  title     = {Bestimmung der metabolischen Aktivit{\"a}t von Mikroorganismen w{\"a}hrend des Biogasbildungsprozesses},
  series = {9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]},
  journal   = {9. Dresdner Sensor-Symposium : Dresden, 07.-09. Dezember 2009 / Gerlach, Gerald ; Hauptmann, Peter [Hrsg.]},
  publisher = {TUDpress},
  address   = {Dresden},
  isbn      = {978-3-941298-44-6},
  pages     = {201 -- 204},
  year      = {2009},
  language  = {de}
}
@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}
}
@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}
}
@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{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{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}
}
@phdthesis{Werner2014,
  author    = {Werner, Frederik},
  title     = {Development of light-addressable potentiometric sensor systems and their applications in biotechnological environments},
  pages     = {XI, 149 S.},
  year      = {2014},
  language  = {en}
}
@inproceedings{GroebelWernerJoerresetal.2011,
  author    = {Groebel, Simone and Werner, Frederik and J{\"o}rres, Niklas and Jansen, F. and Kasper, Katharina and Schiffels, Johannes and Sprenger, B. and Baumann, Marcus and Sch{\"o}ning, Michael Josef and Selmer, Thorsten},
  title     = {Entwicklung einer Sensor-{\"U}berwachung f{\"u}r Biogasanlagen auf Basis von Prozessdaten einer Parallelanlage},
  series = {10. Dresdner Sensor-Symposium : Dresden, 5. - 7. Dezember 2011 ; miniaturisierte analytische Verfahren, Hochtemperatur-Sensoren, Sensoren f{\"u}r Bioprozess- und Verfahrenstechnik, Sensoren f{\"u}r die Medizin, Chemische Verfahrenstechnik, Lebensmittelanalytik, innovative Sensorl{\"o}sungen, Sensoren f{\"u}r die Wasserqualit{\"a}t, Selbst{\"u}berwachung / Gerald Gerlach ... (Hg.)},
  booktitle = {10. Dresdner Sensor-Symposium : Dresden, 5. - 7. Dezember 2011 ; miniaturisierte analytische Verfahren, Hochtemperatur-Sensoren, Sensoren f{\"u}r Bioprozess- und Verfahrenstechnik, Sensoren f{\"u}r die Medizin, Chemische Verfahrenstechnik, Lebensmittelanalytik, innovative Sensorl{\"o}sungen, Sensoren f{\"u}r die Wasserqualit{\"a}t, Selbst{\"u}berwachung / Gerald Gerlach ... (Hg.)},
  publisher = {TUDpress},
  address   = {Dresden},
  isbn      = {978-3-942710-53-4},
  doi       = {10.5162/10dss2011/4.3},
  pages     = {81 -- 84},
  year      = {2011},
  abstract  = {Beim Ausbau nachhaltiger, regenerativer Energieversorgung hat die Umwandlung von organischer Biomasse in Biogas ein großes Potential. Der zugrundeliegende, komplexe biologische Prozess wird noch immer unzureichend verstanden und bedarf systematischer Untersuchungen der Prozessparameter, um einen hohen Ertrag bei guter Gasqualit{\"a}t zu erm{\"o}glichen. Die Fragestellungen zur Entschl{\"u}sselung des Prozesses sind sowohl verfahrenstechnischer als auch mikrobiologischer Natur. Aus mikrobiologischer Sicht ist die Kenntnis der tats{\"a}chlich beteiligten prozesstragenden Mikroorganismen von erheblicher Bedeutung, aus verfahrenstechnischer Sicht die Kenntnis der physikalischen und chemischen Faktoren, welche die mikrobiologischen Prozesse und kontrollieren. Im Zusammenspiel aller dieser Parameter wird die Biogasbildung bef{\"o}rdert oder behindert, bis zum Abbruch des Prozesses. Eine m{\"o}gliche Kontrollmethode ist die Messung der metabolischen Aktivit{\"a}t prozesstragender Organismen. Diese soll, beruhend auf fundierten Prozessdaten, gewonnen durch eine Parallelanlage, mit einem lichtadressierbaren potentiometrischen Sensor-System (LAPS) realisiert werden. Dieser Sensor ist in der Lage, pH-Wert-{\"a}nderungen zu detektieren, die durch den Stoffwechsel der auf dem Chip immobilisierten Organismen hervorgerufen werden, um eine Online-{\"U}berwachung von Biogasanlagen zu erm{\"o}glichen.},
  language  = {de}
}
@article{WernerSchusserSpalthahnetal.2011,
  author    = {Werner, Frederik and Schusser, Sebastian and Spalthahn, Heiko and Wagner, Torsten and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef},
  title     = {Field-programmable gate array based controller for multi spot light-addressable potentiometric sensors with integrated signal correction mode},
  series = {Electrochimica Acta},
  volume    = {56},
  journal   = {Electrochimica Acta},
  number    = {26},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0013-4686},
  doi       = {10.1016/j.electacta.2011.03.012},
  pages     = {9656 -- 9660},
  year      = {2011},
  abstract  = {A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction.},
  language  = {en}
}
@article{WagnerMiyamotoWerneretal.2011,
  author    = {Wagner, Torsten and Miyamoto, K. and Werner, Frederik and Sch{\"o}ning, Michael Josef and Yoshinobu, T.},
  title     = {Flexible electrochemical imaging with "zoom-in" functionality by using a new type of light-addressable potentiometric sensor},
  publisher = {IEEE},
  address   = {New York},
  pages     = {2133 -- 2135},
  year      = {2011},
  language  = {en}
}
@article{WagnerWernerMiyamotoetal.2010,
  author    = {Wagner, Torsten and Werner, Frederik and Miyamoto, Ko-ichiro and Ackermann, Hans-Josef and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef},
  title     = {FPGA-based LAPS device for the flexible design of sensing sites on functional interfaces},
  series = {Physica Status Solidi (A). 207 (2010), H. 4},
  journal   = {Physica Status Solidi (A). 207 (2010), H. 4},
  isbn      = {1862-6300},
  pages     = {844 -- 849},
  year      = {2010},
  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}
}