Scanning Electrochemical Microscopy

Abstract

Scanning electrochemical microscopy (SECM) is a method of local probe microscopy based on the displacement of an ultramicroelectrode (UME) in the vicinity of an interface. The UME has at least one dimension in the micrometer range. It is extremely useful in modern electroanalysis for the characterization of surfaces by imaging electroactive and nonelectroactive materials or for obtaining quantitative data on specific analytes or processes by studying the reactions occurring on the surface of a substrate. It operates through several modes (feedback, generation/collection, penetration, etc…) and allows evaluating kinetics of chemical reactions, studying biological cells, achieving localized surface modifications or imaging surfaces. More recently, scanning electrochemical cell microscopy (SECCM) was developed to allow obtaining high spatial resolution images. SECCM is derived from SECM and consists of a probe which is a sharp double barrel capillary (nanopipette), with both compartments containing a quasi-reference electrode or quasi-reference counter electrode (QRCE) and filled with an electrolytic solution.