Mapping Surface Charge of Individual Microdomains with Scanning Ion Conductance Microscopy

We further describe a protocol for the investigation of surface charge with scanning ion conductance microscopy. The protocol measures current-voltage curves at positions close to and far from the surface of interest and reports the differential response. The data can be interpreted in terms of rectification ratios, an intuitive quantity for such studies. With this protocol, we further investigate the effect of electrolyte concentration and study the influence of scan potential on surface charge measurement on chemically modified surfaces.