Enhanced Electrochemiluminescence in a Microwell Bipolar Electrode Array Prepared with an Optical Fiber Bundle

Abstract

AbstractThe creation of microwells on an electrode surface has been used to improve the electrode performance. Herein, we report the fabrication of a microwell bipolar electrode array (MBEA) by selectively etching a fiber core and coating a thin gold layer on one pole of optical fiber bundle. The remote electrochemiluminescence (ECL) sensing platform is developed with the combination of the MBEA and ECL, such that light emission is generated at the distal face of the optical fiber bundle and detected at its proximal face. The resulting microwells in the MBEA can enhance the ECL generation, and produce a bell‐like ECL emission, for which higher light intensity is measured in the center of the fiber core than around its periphery. Then, it is revealed in theoretical simulations that the parabolic‐shaped bottom in the microwell induces the strong overlapped diffusion fields in its center and promotes the generation of ECL there. Finally, the application of MBEA is demonstrated in the detection of nicotinamide adenine dinucleotide (NADH).