Electrocatalytic oxidation of norepinephrine at a glassy carbon electrode modified with single wall carbon nanotubes

The voltammetric behavior of norepinephrine (NE) was studied at a glassy carbon (GC) electrode modified with single wall carbon nanotubes (SWNTs). In pH 5.72 B-R buffer solution, the SWNT-modified electrode shows high electrocatalytic activity toward NE oxidation. One well-defined reversible redox couple is obtained at scan rates lower than 0.15 V s(-1). The peak current increases linearly with the concentration of NE in the range of 1.0 x 10(-5) - 1.1 x 10 (3) mol dm(-3). The detection limit is 6.0 x 10(-6) mol dm(-3) and the diffusion coefficient (D) of NE is 8.53 x 10 (6) cm(2)s(-1). The SWNT was characterized with scanning electron microscope (SEM). Furthermore, the SWNT-modified electrode has favorable electrocatalytic activity with dopamine, epinephrine, and ascorbic acid.