Vertically aligned nanowire array-based sensors and their catalytic applications

This chapter investigates the fabrication of metallic nanowire arrays and their application as sensors or biosensors to determine glucose, glutamate and H 2O2. Nanowire-based material provides a very high electrochemically active surface area, thereby leading to very high detection sensitivity. To date, noble metals, such as platinum (Pt), gold (Au), silver (Ag) and their alloys, have been extensively investigated as anodic materials in the design of non-enzymatic sensor surfaces. Vertically aligned structures such as free-standing nanowire arrays are particularly useful for sensing and biosensing applications due to their high sensitivity to surface interactions. Although nanowires have been fabricated by various methods, a simple fabrication technique which incurs reasonable costs for practical applications is highly desired. In this chapter, a template-based fabrication of nanowire arrays of Au, Pt and nickel (Ni) will be described. These materials have been characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The catalytic activity and the suitability of these materials as electrochemical sensors have been investigated by cyclic voltammetry and amperometry.