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

•The cationic surfactant CTAB was electropolymerized on GCE.•The electropolymerization of CTAB must be carried out in strong acidic solution.•Poly(CTAB) exhibits a nanoporous structure and is highly uniform and adhesive.•Poly(CTAB)/GCE catalyzed the oxidation of several biomolecules.

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 1.2 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 μM, 1–1000 μM, 1–1000 μM and 0.5–1000 μM with detection limits of 0.11 μM, 0.33 μM, 0.44 μM and 0.11 μM, respectively. Satisfactory results were obtained when poly(CTAB)/GCE was applied to the simultaneous determination of DA, UA, Trp and TP in urine samples.

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