Carboxy-functionalized Multi-Walled Carbon Nanotubes Hybridized with Poly(Xanthurenic Acid) Enhance the Electrocatalytic Oxidation of Ascorbic Acid, Dopamine, and Uric Acid

摘要

Glassy carbon electrodes (GCEs) were modified with different types of hybrid composites preparedfrom poly(xanthurenic acid), single-walled carbon nanotubes (SWCNT), and multi-walled carbonnanotubes (MWCNT). They were studied with respect to the simultaneous determination of ascorbicacid (AA), dopamine (DA), and uric acid (UA). The hybrid composite GCE displays a relatively lowoverpotential and high current response for the analytes. Differential pulse voltammetry (DPV) showsgood selectivity and a linear response in the concentration ranges of 10 M.3 mM, 5 M65M, and 5 M.65 mM for AA, DA, and UA, respectively. The sensitivities are 145.8, 2036.8, and-1 -2 338.6 A mM cm , and the detection limits are 10 M, 1 M, and 5 M (at an S/N of 3). Themethod was successfully applied to the determination of the three species in spiked urine samples.