ABSTRACT
Scanning electrochemical microscopy (SECM) has been used with a variety of different substrates, including metals, polymers, semiconductors, and biological specimens. The SECM instrument basically consists of a combination of familiar electrochemical components and those used in a scanning tunneling microscope for manipulating a tip and a substrate at high resolution and for acquiring the data. Most of the reported SECM images have used a constant height mode in which the tip is rastered across the substrate at a constant reference plane above the sample surface. A detailed description of the circuit to perform constant current imaging over a mixed insulator and conductor surface with SECM, demonstrated by imaging a Kel-F/Au composite electrode, has been published. Cone-Shaped microelectrodes type of tip is useful as an SECM tip for directly probing interfacial films and for imaging. While most of the SECM work has been carried out with amperometric measurements, potentiometric probing is also possible.
