An 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)-immobilized electrode for the simultaneous detection of dopamine and uric acid in the presence of ascorbic acid

An 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)-immobilized carbon nanotube (CNT) electrode was used to simultaneously detect dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) with differential pulse voltammetty. When ABTS was immobilized onto the CNT electrode in the presence of DA, UA and 100 mu M AA, the sensitivity to DA increased from 0.600 (+/- 0.013) to 1334 (+/- 0.010) mu A/mu M in the concentration ranges of 0.90-10 mu M and 1.87-20 mu M, respectively, and the sensitivity to UA increased from 0.030 (+/- 0.005) to 0.078 (+/- 0.006) mu A/mu M in the concentration ranges of 2.16-240 mu M and 3.07-400 mu M, respectively. These findings demonstrate that the ABTS-immobilized CNT electrode attained a higher sensitivity to UA and also a wider linear range of concentrations. (C) 2013 Elsevier B.V. All rights reserved.