Fabrication of High-Density and Superuniform Gold Nanoelectrode Arrays for Electrochemical Fluorescence Imaging

Abstract

Nanoelectrode arrays have been widely used in electroanalytical applications. The challenge is to develop low-cost and simple approaches to the fabrication of super-uniform and ultra-small nanoelectrode arrays for improving analytical performance and imaging resolution. Here, super-uniform and high-density gold nanoelectrode arrays with tunable electrode diameter and interelectrode distance have been fabricated by electrodeposition followed by a simple mechanical polishing process. The fabricated free-standing arrays have high density (10⁸ cm^-2) of nanoelectrodes (60 nm, 140 nm and 200 nm in diameter), and can be used as closed bipolar electrode arrays to image electrochemical heterogeneity with micrometer spatial resolution. With the help of confocal microscope, individual nanoelectrodes can be visualized and resolved from the reflected light. Thus, the nanoelectrode arrays are promising in electrochemical imaging with high spatial resolution.