Single-cellular electroanalytical chemistry at micro-nano interfaces

Knowledge on the behavior of an individual cell is of critical importance because even genetically identical cells showed large variation. It has become an essential project to design and develop single-cell in-situ analysis techniques with high sensitivity, high selectivity, and high spatiotemporal resolution in the field of analytical chemistry. Aiming at urgent challenges in the field of single-cell analysis, such as the low sensitivity and background interference, we proposed many new mechanisms for electrochemical analysis and constructed a lot of high-sensitive optoelectronic micro-nano interfaces. With these new optoelectronic micro-nano interfaces, the applicant developed a series of single-cell imaging techniques to solve scientific problems. For example, the applicant proposed Fermi level-charge theory that straightly decreases the detection limit of faraday current to attoampere level, six orders smaller than current methods, which allows for the observation of single-molecular level electron transfer events. we elucidate the intracellular factors that determine this output limit by monitoring the respiratory-driven shrinking kinetics of a single magnetite nanoprobe immobilized on a single Shewanella oneidensis MR-1 cell with plasmonic imaging. We proposed label-free structural color microscopy and demonstrated that Shewanella oneidensis MR-1 cells show unique structural color scattering, changing with the redox state of cytochrome complexes in the outer membrane. it provides a potential platform for further exploring the electron transfer mechanism of subcellular structure.