A critical review: Advanced electrochemical analysis based on nanoscale scanning electrochemical microscopy

• SECM enables real-time surface and interfacial analysis with spatial resolution in an electrochemical environment. • Nanoscale SECM can be utilized for better electroanalysis. • Nanotip fabrication, instrumentation and basic principles of SECM, and analytical applications were summarized. Electroanalysis is a type of analytical method used to study an analyte by measuring its electrical properties in an electrochemical cell. It has been widely used because it is a relatively simple and inexpensive technique, has a low detection limit and is able to measure original electrical signals. Electroanalysis has advanced with the development of nanotechnology, offering new opportunities for analysis. Scanning electrochemical microscopy (SECM) is a probe-based surface analysis instrument that enables real-time surface and interfacial analysis with spatial resolution in an electrochemical environment. In this review, we focus on the use of nanoscale SECM for improved electroanalysis. After introducing the fabrication, characterization, and modification of nanoelectrodes, which are the key to enabling nanoscale SECM, we introduce the instrumentation and fundamental principles of SECM. Several examples are provided to illustrate the advanced electroanalysis of photo-electrocatalysts and biosystems based on nanoscale SECM, which will be utilized as a more powerful electroanalytical tool in the future when combined with other analytical instruments.