Chapter 32 From microelectrodes to nanoelectrodes

Abstract

Publisher Summary Initially, little attention was paid to the influence that size and geometry of electrode surface have on electrochemical processes. The reduction of the electrode dimensions is considered from two points of view: theoretical and practical. From a practical point of view, the reduction of the electrode dimensions shows advantages and drawbacks. On one hand, minimal dimensions are desired when the application exploits some of the characteristics inherent to electrodes with reduced dimensions (ERD). For single electrodes, microelectrodes or ultramicroelectrodes have shown important advantages in a wide variety of applications although improvements can be obtained with ERDs slightly smaller. In this context, ERDs in the 100-nm range promise a successful future. Apart from theoretical and instrumental limitations, the use of single nanoelectrodes (NEs) is still in its infancy and the enhancement in the spatial resolution of the scanning electrochemical microscopy is the more noteworthy of their applications. However, experimental results (like the low detection limits achieved with NE ensembles) have proved that grouped NEs are suitable devices for several goals. It has to be indicated that the actual trend for miniaturizing analytical systems implies the use of ERDs or NEs in electroanalytical applications. With this aim, highly packed ERD or NE arrays have demonstrated to be suitable candidates from the analytical and economical criterion.