The electropolymerization of CTAB on glassy carbon electrode for simultaneous determination of dopamine, uric acid, tryptophan and theophylline

The electropolymerization of cetyltrimethylammonium bromide (CTAB) on glassy carbon electrode (GCE) was carried out when GCE was cycled in 0.1 M sulfuric acid containing CTAB from -0.8 V to 12 V for several cycles. Scanning electron microscopy (SEM) study confirmed the formation of nanoporous poly(CTAB) thin film on GCE, which is highly uniform and adhesive. Cyclic voltammetric (CV) shows that poly(CTAB)/GCE exhibited great catalytic capability for the oxidation of dopamine (DA), uric acid (UA), tryptophan (Trp) and theophylline (TP) by enhancing their oxidation currents. In pH 7.0 0.1 M PB solution containing DA, UA, Trp and TP, the linear calibration plots for DA, UA, Trp and TP were obtained over the range of 0.5-1000 mu M, 1-1000 mu M, 1-1000 and 0.5-1000 mu M with detection limits of 0.11 mu M, 033 mu M, 0.44 M and 0.11 mu M, respectively. Satisfactory results were obtained when poly(CTAB)/GCE was applied to the simultaneous determination of DA, UA, Trp and TP in urine samples. (C) 2016 Elsevier B.V. All rights reserved.