Development of a scanning electrochemical microscopy-based micropipette and its application to analysis of topographic change of single-cell

Scanning electrochemical microscopy (SECM) is useful for analyzing various cellular responses. We have combined a micropipette (MP) with SECM to perform quantitative solution delivery to single cells. In this system, since the concentrations of electrochemical mediators are changed by the volume of solution delivered from the MP, we constructed a feedback control system to regulate MP delivery by SECM-detected signals. Cellular responses induced by MP delivery could be monitored by the SECM, and cell apoptosis was successfully detected by adding a kinase inhibitor of two orders of magnitude less than what is required in the conventional method. The SECM-based MP can activate a target cell, requiring a minimal amount of agent, and can continually examine target cell responses. This system improves the accuracy of delivery from the MP and is useful for single-cell analysis.