Applications of nanoelectrodes

N. V., Streeter, I., and Baron, R. (2008) Design, fabrication, characterisation and application of nanoelectrode arrays. Chemical Physics Letters, 459 (1-5), 1-17. 

The first part of this section focuses on the main characteristics and fabrication techniques used for obtaining templating membranes and depositing metal nanostructures by suitable electroless and elecuochemical procedures. Methods such as sol-gel (10-12) or chemical vapor deposition (10, 13), which have been used primarily for the template deposition of carbon, oxides, or semiconducting-based materials, will not be considered here in detail. The second part of the section focuses on the electrochemical properties of the fabricated nanomaterials with emphasis on the characteristics and applications of nanoelectrode ensembles (NEEs). 

The practical applications of nanoelectrodes continue to diversify, but it is only in recent years that our ability to fabricate well-characterised electrodes has enabled confident interpretation of the associated electrochemical measurements. In this section we divide the latest developments into three themes (i) fundamental studies relating to heterogeneous electron transfer at nanoelectrodes (ii) sensing applications of nanoelectrodes and their arrays and (iii) electrochemical imaging using nanoelectrodes. 

Experimental studies describing the preparation and application of nanoelectrodes, nanopore electrodes, and conical nanopores have been extensively reported over the past few decades, including several reviews. The focus of this chapter is on providing a unified treatment of EDL effects of the behavior of these structures. 

Bulk nanostructured materials are soUds with nanosized microstructure. Their basic units are usually nanoparticles. Several properties of nanoparticles are useful for applications in electrochemical sensors [67], However, their catalytic behavior is one of the most important. The high ratio of surface atoms with free valences to the total atoms has led to the catalytic activity of nanostructured SEs being used in electrochemical reactions. The catalytic properties of nanoparticles could decrease the overpotential of electrochemical reactions and even provide reversibility of redox reactions, which are irreversible at the bulk metal SE [68], Multilayers of conductive nanoparticles assembled on electrode surfaces produce a high porous surface with a controlled microenviromnent. These structures could be thought of as assemblies of nanoelectrodes with controllable areas. 

More recent works have demonstrated the application of numerical simulation to exploring non-uniformly accessible 3D nanoelectrode geometries. For example, Streeter and Compton employed the finite difference approach to examine diffusion limited currents at isolated spheroidal and hemispheroidal nanoparticle electrodes immobilized on inert substrates. Building on this. Ward et al. used numerical methods to simulate isolated spherical nanoparticle voltammetry in the limit of irreversible electron transfer kinetics and derived a simple expression describing the voltammetric wave-shape ... 

Nanostructured electrodes Theoretical aspects Electrode materials and morphology Preparation of nanoelectrodes Applications... 

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