Towards addressability of light-addressable potentiometric sensors: Shunting effect of non-illuminated region and cross-talk

  • 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.

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Metadaten
Author:Arshak PoghossianORCiD, Frederik WernerORCiD, V. V. Buniatyan, Torsten WagnerORCiD, K. Miamoto, T. Yoshinobu, Michael Josef SchöningORCiD
DOI:https://doi.org/10.1016/j.snb.2017.01.047
ISSN:0925-4005
Parent Title (English):Sensor and Actuators B: Chemical
Publisher:Elsevier
Place of publication:Amsterdam
Document Type:Article
Language:English
Year of Completion:2017
Issue:244
First Page:1071
Last Page:1079
Link:https://doi.org/10.1016/j.snb.2017.01.047
Zugriffsart:campus
Institutes:FH Aachen / Fachbereich Medizintechnik und Technomathematik
FH Aachen / INB - Institut für Nano- und Biotechnologien
collections:Verlag / Elsevier