ABSTRACT
Most scanning electrochemical microscopic (SECM) experiments are conducted in the amperometric mode, yet microelectrodes have long been used as potentiometric devices. Not surprisingly, several SECM investigations have been reported where the tip was operated in the potentiometric mode. In this chapter, we present the background necessary to understand the differences between amperometric and potentiometric SECM applications, we report the progress made in the –eld of potentiometric microelectrodes, we consider the issues speci–c to the potentiometric mode of SECM, and we highlight some of the studies involving potentiometric SECM tips. Starting with an historical perspective, we highlight the key discoveries that facilitated the development and applications of micropotentiometric probes and include recent improvements in detection limits. We review fabrication recipes and cover basic theoretical principles, properties, and technical operational details. In the second half of this chapter, we discuss SECM potentiometric applications and emphasize differences with the conventional amperometric mode.
