Ultramicroelectrodes offer several unique characteristics which enable new types of
electrochemical measurements. These include: 1) small size; 2) minimisation of iR effects; 3) rapid
response; and 4) steady-state response at moderate times. These features enable experiments as
diverse as in vivo electrochemistry, electrochemistry in pharmacology, nanoelectrochemistry,
electrochemistry in solvents such as benzene, microsecond electrochemistry, and flow-rate
independent electrochemistry. Thus, it is apparent that the use of ultramicroelectrodes has become a
rapidly growing area of interest. In this paper, the attributes of ultramicroelectrodes, its construction,
the equations of diffusion, and key applications of electrochemistry at ultramicroelectrodes, are
analysed.