Au nanoparticle-graphene quantum dot-Nafion modified electrode for voltammetric determination of dopamine

Abstract

In this work, glassy carbon electrode was modified by gold nanoparticle-graphene quantum dots-Nafion (Au-GQDs-Nafion) nanocomposite and used for voltammetric determination of trace dopamine. The properties of the as-prepared material were characterized by UV-vis spectrometry, Fluorescence spectrometry, and TEM. The Au-GQDs-Nafion composite showed the excellent synergistic effect for electrochemical detection of dopamine (DA). Under optimum conditions, the differential pulse voltammetric (DPV) peak current and the concentration of DA displayed a linear range from 2 μM to 50 μM with the detection limit of 0.84 μM. Furthermore, the as-prepared electrode also showed selectivity toward DA detection in the existence of uric acid (UA) and ascorbic acid (AA). The interference experiments showed that most of the ions did not show obvious influence on the detection of DA. The modified electrode presented reasonable stability and reproducibility in voltammetric sensing of DA, and also was applied to human urine samples.