title: Light-Addressable Potentiometric Sensors for Quantitative Spatial Imaging of Chemical Species.
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.
authors.affiliation: Department of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan; email: nov@ecei.tohoku.ac.jp.|Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yoshinobu
authors.affiliation: Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan.
authors.forename: Ko-Ichiro
authors.initials: KI
authors.lastname: Miyamoto
authors.affiliation: Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan.
authors.forename: Carl Frederik
authors.initials: CF
authors.lastname: Werner
authors.affiliation: Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany.|Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany.
authors.forename: Arshak
authors.initials: A
authors.lastname: Poghossian
authors.affiliation: Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany.|Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Wagner
authors.affiliation: Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany.|Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schöning
keywords: LAPS; bioimaging; biosensor; chemical imaging sensor; pH sensor