Electrochemical Visualization of Membrane Proteins in Single Cells at a Nanoscale Using Scanning Electrochemical Cell Microscopy
Rong Jin, Wenting Zhou, Yanyan Xu, Dechen Jiang, Danjun Fang
Abstract
The electrochemical visualization of proteins in the plasma membrane of single fixed cells was achieved with a spatial resolution of 160 nm using scanning electrochemical cell microscopy. The model protein, the carcinoembryonic antigen (CEA), is linked with a ruthenium complex (Ru(bpy) 3 2+ )-tagged antibody, which exhibits redox peaks in its cyclic voltammetry curves after a nanopipette tip contacts the cellular membrane. Based on the potential-resolved oxidation or reduction currents, an uneven distribution of membrane CEAs on the cells is electrochemically visualized, which could only be achieved previously using super-resolution optical microscopy. Compared with current electrochemical microscopy, the single-cell scanning electrochemical cell microscopy (SECCM) strategy not only improves the spatial resolution but also utilizes the potential-resolved current from the antibody–antigen complex to increase electrochemical imaging accuracy. Eventually, the electrochemical visualization of cellular proteins at the nanoscale enables the super-resolution study of cells to provide more biological information.