THE PREPARATION OF TIPS FOR SCANNING ELECTROCHEMICAL MICROSCOPY

In this chapter, several methods for the fabrication of different types of amperometric tips suitable for SECM are described. We have also suggested some methods for microelectrode fabrication, which have not yet been tested for SECM but may provide alternative ways for its tip preparation. Section II.A describes the techniques for the preparation of various metallic microelectrodes, including Pt, Ir-Pt, Au, Hg, and W. The manufacture of carbon microelectrodes is presented in Section II.B. Most of these tips are encapsulated in or supported with glass capillaries. Other coating materials and techniques are treated in Section II.C. 

While most of the SECM work has been carried out with amperometric tips for measuring feedback current or for use in the generation/collection mode, other types of tips such as potentiometric and enzymatic tips are also possible but are only briefly described in Section II.D. The readers who are interested in these tips are encouraged to refer to the appropriate chapters in this monograph. Finally, Section III deals with an approach to determining the shape of an ultramicroelectrode from its SECM response. 

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