TY  - JOUR
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Buniatyan, V. V.
A1  - Wagner, Torsten
A1  - Miamoto, K.
A1  - Yoshinobu, T.
A1  - Schöning, Michael Josef
T1  - Towards addressability of light-addressable potentiometric sensors: Shunting effect of non-illuminated region and cross-talk
JF  - Sensor and Actuators B: Chemical
N2  - The LAPS (light-addressable potentiometric sensor) platform is one of the most attractive approaches for chemical and biological sensing with many applications ranging from pH and ion/analyte concentration measurements up to cell metabolism detection and chemical imaging. However, although it is generally accepted that LAPS measurements are spatially resolved, the light-addressability feature of LAPS devices has not been discussed in detail so far. In this work, an extended electrical equivalent-circuit model of the LAPS has been presented, which takes into account possible cross-talk effects due to the capacitive coupling of the non-illuminated region. A shunting effect of the non-illuminated area on the measured photocurrent and addressability of LAPS devices has been studied. It has been shown, that the measured photocurrent will be determined not only by the local interfacial potential in the illuminated region but also by possible interfacial potential changes in the non-illuminated region, yielding cross-talk effects. These findings were supported by the experimental investigations of a penicillin-sensitive multi-spot LAPS and a metal-insulator-semiconductor LAPS as model systems.
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.snb.2017.01.047
SN  - 0925-4005
IS  - 244
SP  - 1071
EP  - 1079
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Scheja, Sabrina
A1  - Jessing, Max
A1  - Metzger-Boddien, Christoph
A1  - Keusgen, Michael
A1  - Poghossian, Arshak
T1  - Label-Free DNA Detection with Capacitive Field-Effect Devices—Challenges and Opportunities
JF  - Proceedings
N2  - 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.
Y1  - 2017
U6  - http://dx.doi.org/10.3390/proceedings1080719
SN  - 2504-3900
N1  - This article belongs to the Proceedings of "Proceedings of the 5th International Symposium on Sensor Science (I3S 2017)"
VL  - 1
IS  - 8
SP  - Artikel 719
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Miyamoto, Ko-ichiro
A1  - Werner, Frederik
A1  - Poghossian, Arshak
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors for quantitative spatial imaging of chemical species
JF  - Annual Review of Analytical Chemistry
N2  - 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.
Y1  - 2017
U6  - http://dx.doi.org/10.1146/annurev-anchem-061516-045158
SN  - 1936-1327
VL  - 10
SP  - 225
EP  - 246
PB  - Annual Reviews
CY  - Palo Alto, Calif.
ER  -