Studies of charge transfer at liquid | liquid interfaces and bilayer lipid membranes by scanning electrochemical microscopy

The principles of scanning electrochemical microscopy (SECM) and its application to studies of electron transfer at the interface between two immiscible electrolyte solutions are reviewed. The results of SECM measurements with a number of redox couples at the bare liquid | liquid interface or an interface with a lipid monolayer suggest that the electron transfer follows that predicted by Marcus theory, with evidence for an inverted region. The SECM can also be used to probe processes at bilayer lipid membranes.