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

In this work, glassy carbon electrode was modified by Nafion coated gold nanoparticle-graphene quantum dots (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 the electrochemical detection of dopamine (DA). Under optimum conditions, the differential voltammetric (DPV) peak current and the concentration of DA displayed a linear range of 2 mu M to 50 mu M with the detection limit of 0.84 mu M. Furthermore, the as-prepared electrode also showed selectivity toward DA detection in the existence of uric acid (UA) and ascorbic acid (AA). The interference experiment 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 the voltammetric determination of DA, and also the nanocomposite was applied for the real sample analysis in human urine.