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

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 x 10(-6) cm(2) s(-1). The peak current increases linearly with the concentration of UA in the range of 4.0 x 10(-6)-7.0 x 10(-4) M. The detection limit is 1.0 x 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. (C) 2002 Elsevier Science B.V. All rights reserved.