Poly(glycine)/graphene oxide modified glassy carbon electrode: Preparation, characterization and simultaneous electrochemical determination of dopamine, uric acid, guanine and adenine

Abstract

A novel poly(glycine) (p-GLY)/graphene oxide (GO) composite based sensor (p-GLY/GO) was successfully prepared on glassy carbon electrode by simple electropolymerization. Electrochemical responses of analytes on p-GLY/GO modified electrode were studied by cyclic voltammetry and differential pulse voltammetry. The results demonstrated that p-GLY/GO modified electrode showed a favorable application for the simultaneous determination of dopamine (DA), uric acid (UA), guanine (GU) and adenine (AD). Owing to the synergistic effect of p-GLY and GO, the oxidation peaks of four analytes separated well from each other, and the potential separations of oxidation peaks of DA-UA, UA-GU and GU-AD were large up to 170, 350 and 300 mV, respectively. As-prepared p-GLY/GO modified electrode offered wide linear responses for DA, UA, GU and AD over the ranges of 0.20–62, 0.10–105, 0.15–48 and 0.090–103 μM with detection limits of 0.011, 0.061, 0.026 and 0.030 μM (S/N = 3), respectively. Moreover, p-GLY/GO modified electrode presented favorable selectivity, stability and reproducibility, which was a promising candidate as an electrochemical sensor for the simultaneous determination of DA, UA, GU and AD.