Perspective on Scanning Electrochemical Probe Microscopy in Single-Cell Imaging.

Single-cell analysis is essential for probing cellular heterogeneity and understanding biological and disease mechanisms. Cellular imaging plays a key role in this field by providing critical spatiotemporal and functional information. Scanning electrochemical probe microscopy (SEPM), a kind of electrochemical imaging technique using micro/nanometer-sized probes to scan cells, can provide information on cellular topography and various interfacial processes in a nondestructive and real-time manner with high spatiotemporal resolution, therefore becoming a powerful tool for single-cell analysis. In this perspective, we systematically review the advances of three SEPM techniques (including scanning electrochemical microscopy (SECM), scanning ion conductance microscopy (SICM), and scanning electrochemical cell microscopy (SECCM) for single-cell analysis, including imaging cellular topography, membrane protein distribution, metabolic activity, surface charge, and mechanical property. We also discuss the current challenges in enhancing spatiotemporal resolution, detection sensitivity, and imaging throughput and realizing the multiparameter monitoring capability of SEPM for single-cell studies. Last, we highlight their promising development directions, such as high-performance imaging, multimodal integration, functionalized probes, 4D monitoring, and intelligent data analysis, with which SEPM can support more in-depth investigation in cell function studies.