Light-Addressable Potentiometric Sensors in Microfluidics

Abstract

Light-addressable potentiometric sensor (LAPS) is an electrochemical sensor based on the field-effect principle of semiconductor. It is able to sense the change of Nernst potential on the sensor surface, and the measuring area can be controlled by the illumination. Due to the unique light-addressable ability of LAPS, the chemical imaging system constructed with LAPS can realize the two-dimensional image distribution detection of chemical/biomass. In this paper, the advantages of LAPS as sensing unit of microelectrochemical analysis system are summarized. Then, the greatest development of LAPS analysis system is explained and discussed. Especially, this paper focused on the research of ion diffusion, enzymatic reaction, microbial metabolism and droplet microfluidics by using LAPS analysis system. Finally, the development trends and prospects of LAPS analysis system are illustrated.

A ratiometric, fluorometric approach for surface charge mapping of biosilica features

“…17 There have been considerable advances in the application of electrochemistry at the nanoscale to the study of cellular systems and materials 18 including the development of scanning electrochemical microscopy (SECM) in conjunction with nanometer-sized electrodes. 19 Recent advances in light addressable potentiometric sensors (LAPS) are able to map surface charge on cells on the side adjacent to an electrode 20,21 Although non-linear optical methods have been developed to study localised water at interfaces 22 to the best of our knowledge, no optical technique to measure surface charge on mineral structures embedded in biological materials is available. Where such a technique would be useful is in the study of biological silicification where many structural particulate arrangements at the nanoscale exist within a single microscopic sample.…”