Investigation of Multi-Walled Carbon Nanotubes as Electrochemical Electrodes

Individual multi-walled carbon nanotubes were investigated for their usefulness as nanoscale electrochemical electrodes. The nanotubes were mounted on metal-coated atomic force microscopy tips, and the assembly was insulated with Parylene polymer. Approximately 200nm of the nanotube tip was exposed by use of a laser so the entire probe could be immersed in an electrolytic solution with only the nanotube tip left as the electroactive area. The nanotube electrodes were investigated through use of cyclic voltammetry in a solution of 1.0 mM potassium ferricyanide(K3Fe(CN)63-) in a supporting electrolyte of 0.10 M potassium chloride(KCl). It is shown that nanotubes are electrochemically active. 1