A unique approach for electrochemical determination of dopamine by turning off uric acid and ascorbic acid peaks

Abstract

A novel technique was adopted for the electrochemical determination of dopamine and the simultaneous determination of uric acid (UA), ascorbic acid (AA), and dopamine (DA) in buffered phosphate-saline pH 7.4 using a few-layer graphene/Pt (FGP) electrode. In the positive scan, the differential pulse voltammetry (DPV) technique of FGP for UA, DA, and AA revealed widely separated three oxidation peaks. In particular, in the negative scan, the FGP electrode only worked with DA while "turning off" for UA and AA, indicating that small amounts of DA could be easily quantified in the presence of large amounts of UA and AA interferences. In the positive scan, the sensors of UA, DA and AA were determined with a linear range of 10 - 1500 (µM), 1 - 200 (µM), and 5 - 500 (µM), a sensitivity of 136.02, 111.45, and 815.58 (µAcm-2mM-1), and a detection limit of 2.6, 4.0, and 0.4 (µM), respectively. DA was quantified in a negative scan with a linear range of 1 – 50 µM, a sensitivity of 2576.87 (µAcm-2mM-1), and a detection limit of 0.1 (µM). This report presents a novel technique that aims to determine dopamine based on fast and simple electrochemical measurements.