Simultaneous electrochemical investigations of dopamine and uric acid by in situ amino functionalized reduced grahene oxide

Abstract

We have synthesized amino functionalized reduced graphene oxide (NH2-rGO) composite. Bucherer reaction was used for the in situ modification of graphene oxide into the (NH2-rGO). A simple hydrothermal method was utilized for proposed synthesis. Electrochemical sensor was fabricated by drop coating NH2-rGO nanocomposite onto the glassy carbon electrode (GCE) for individual and the simultaneous detection of dopamine (DA) and uric acid (UA). The NH2-rGO materials formation was confirmed by X-ray diffraction, IR, UV and FE-SEM. The electrochemical sensing of DA and UA was examined by cyclic voltammetry and differential pulse voltammetry. For individual detection of DA, the linear responses of current concentration plot was found in the concentration range of 2.04 × 10−4– 2.04 × 10−3 M with detection limit 1.4 × 10−4 M (S/N = 3) and for UA, 1.8 × 10−3– 1.8 × 10−4 M with detection limit 1.67 × 10−4 M (S/N = 3). The NH2-rGO/GCE electrochemical sensor further tested for the simultaneous detection of binary mixtures of DA and UA and found to be high sensitive compared to individual detection of DA and UA at pH 3. Sensor selectivity is demonstrated in the presence of 2 × 10−4 M concentrations of potentially active interfering compounds including dopamine, uric acid and glucose isomers.