@article{SchoeningBronderWuetal.2017,
  author    = {Sch{\"o}ning, Michael Josef and Bronder, Thomas and Wu, Chunsheng and Scheja, Sabrina and Jessing, Max and Metzger-Boddien, Christoph and Keusgen, Michael and Poghossian, Arshak},
  title     = {Label-Free DNA Detection with Capacitive Field-Effect Devices—Challenges and Opportunities},
  series = {Proceedings},
  volume    = {1},
  journal   = {Proceedings},
  number    = {8},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2504-3900},
  doi       = {10.3390/proceedings1080719},
  pages     = {Artikel 719},
  year      = {2017},
  abstract  = {Field-effect EIS (electrolyte-insulator-semiconductor) sensors modified with a positively charged weak polyelectrolyte layer have been applied for the electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge. The EIS sensors are able to detect the existence of target DNA amplicons in PCR (polymerase chain reaction) samples and thus, can be used as tool for a quick verification of DNA amplification and the successful PCR process. Due to their miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge, those sensors can serve as possible platform for the development of label-free DNA chips. Possible application fields as well as challenges and limitations will be discussed.},
  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{WernerMiyamotoWagneretal.2017,
  author    = {Werner, Frederik and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Lateral resolution enhancement of pulse-driven light-addressable potentiometric sensor},
  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.2017.02.057},
  pages     = {961 -- 965},
  year      = {2017},
  abstract  = {To study chemical and biological processes, spatially resolved determination of the concentrations of one or more analyte species is of distinct interest. With a light-addressable potentiometric sensor (LAPS), chemical images can be created, which visualize the concentration distribution above the sensor plate. One important challenge is to achieve a good lateral resolution in order to detect events that take place in a small and limited region. LAPS utilizes a focused light spot to address the measurement region. By moving this light spot along the semiconductor sensor plate, the concentration distribution can be observed. In this study, we show that utilizing a pulse as light excitation instead of a traditionally used continuously modulated light excitation, the lateral resolution can be improved by a factor of 6 or more.},
  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}
}