Tip Preparation and Instrumentation for Nanoscale Scanning Electrochemical Microscopy

In this chapter, the fabrications of different types of amperometric tips facilitated by focused ion beam (FIB) milling, which would be a suitable probe for scanning electrochemical microscopy (SECM) at nanoscale, are described. The chapter describes how these tips were characterized in terms of their shape and approach capability in SECM measurements. It also describes the techniques for the preparation of various types of nanometer- and submicrometer-sized electrodes, including Pt, C, tunneling ultramicroelectrodes (TUMEs), and glass pipets milled by FIB. All tips are encapsulated in or supported with glass capillaries pulled by CO2–laser puller. Since Blaedel and Mabbot reported the use of pyrolytic carbon-thin-film formed by chemical vapor deposition (CVD) from methane as an electrode material, successful application of this approach to fabrication of a disk shape of submicro–micrometer-sized carbon electrodes could be made showing a remarkably good electrochemical behavior, both in water and in organic solutions.