HETEROGENEOUS ELECTRON TRANSFER REACTIONS
The scanning electrochemical microscopy (SECM) concept of bringing a probe close to a phase boundary makes it possible to measure rates of transfer processes across interfaces in a wide range of applications (1). For scientists, ultramicroelectrodes are the ideal probe, since they can be used to simultaneously initiate transfer reactions of electrons and chemical species across phase boundaries by driving chemical reactions and to monitor the response. Such SECM experiments elegantly combine the advantages of ultramicroelectrodes (UME) with those of thin-layer cells (TLC) (2). Thus, the analysis of heterogeneous transfer processes, primarily electron transfer, represents a popular application of the SECM, and further applications are being developed.