Carbon nanohorns/poly(glycine) modified glassy carbon electrode: Preparation, characterization and simultaneous electrochemical determination of uric acid, dopamine and ascorbic acid

摘要

A novel carbon nanohorns/poly(glycine) based sensor was successfully fabricated by electropolymerization of glycine at carbon nanohorns modified glassy carbon electrode for simultaneous determination of uric acid (UA), dopamine (DA) and ascorbic acid (AA). Electrochemical responses of as-prepared electrodes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. Owing to the synergistic effect of carbon nanohorns and poly(glycine), three well defined and separated oxidation peaks were observed. Peak separations between AA and DA, DA and UA at as-prepared electrode were 130 and 120 mV, respectively. The current of the oxidation peaks showed a linear dependent on the concentrations of UA, DA and AA in the range of 2-350 mu M, 1-280 mu M and 30-450 mu M, respectively, and the detection limits were calculated as 0.18, 0.03 and 0.34 mu M (S/N = 3), respectively. Based on the simple preparation and prominent electrochemical properties, the obtained carbon nanohorns/poly(glycine) modified electrode was applied for the simultaneous determination of UA, DA and AA in the urine samples. (C) 2015 Elsevier B.V. All rights reserved.