Investigation of the electrocatalytic behavior of single-wall carbon nanotube films on an Au electrode

Abstract

The voltammetric behavior of uric acid (UA) was studied with an Au electrode modified with single-wall carbon nanotubes (SWNTs). In 0.1 M HAc–NaAc buffer solution (pH 5.0), the SWNT-modified electrode shows high electrocatalytic activity toward UA oxidation. The electro-oxidation of UA is an irreversible diffusion-controlled process with a diffusion coefficient ( D) of 8.85×10 −6 cm 2 s −1. The peak current increases linearly with the concentration of UA in the range of 4.0×10 −6–7.0×10 −4 M. The detection limit is 1.0×10 −6 M. The SWNT was characterized with scanning electron microscopy (SEM). Furthermore, the SWNT-modified electrode has favorable electrocatalytic activity toward dopamine and norepinephrine. This SWNT-modified electrode can also separate the electrochemical responses of uric acid, norepinephrine and ascorbic acid.