Visualization of electrochemical reactions on microelectrodes using light-addressable potentiometric sensor imaging

Visualization of the electrochemical reaction is essential for comprehensively understanding the electrochemical reaction mechanism and precisely characterizing dynamic electrochemical processes. Herein, we propose a simple device that combines light-addressable potentiometric sensor (LAPS) imaging and microelectrodes to serve as a general electroanalysis platform for the label-free sensing and imaging of electrochemical reactions. In this device, two microelectrodes are assembled on the LAPS chip. Electrochemical reactions occurring on the microelectrodes can be qualitatively and quantitatively observed and visualized using a LAPS chip that is sensitive to the reaction products. Validations were performed to monitor the effect of water electrolysis and potassium ferrocyanide oxidation surrounding the microelectrodes, respectively. We believe that this study will provide an excellent platform for the visualization and monitoring of electrochemical reactions and broaden the application scope of LAPS imaging to a general electroanalysis tool that is widely applicable in several fields.