Advances in electro-optical methods for monitoring confined spaces

Understanding the interfacial behaviors of electroactive materials at the electrode is critically important for advancing electrochemical sensing and catalysis. Coupling electrochemistry with optical methods is emerging as a powerful tool for single-entity analysis, favoring in-depth insights into electrochemical processes. This review focuses on recent advances in electro-optical methods for monitoring confined spaces. The effects from light irradiation on the regulation of electrochemical behaviors of probes at nano/microelectrode are discussed, as revealed through collision electrochemistry-based strategies for single-entity analysis. Advances in the coupling of electrochemistry with fluorescence for the detection of single molecules and single cells are summarized. Finally, we highlight the achievements in electrochemical surface-enhanced Raman spectroscopy for interpreting redox reaction mechanisms at metal confinement.