▎ 摘　　要

A sensitive and selective electrochemical sensor based on three-dimensional graphene hydrogel and gold nanoparticles nanocomposite (3DGH-AuNPs) for simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA) has been successfully developed in present work. The morphologic appearance and crystal structure of the 3DGH-AuNPs nanocomposite were studied by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray Spectrometer (EDX). The electrochemical characteristics and catalytic behavior of prepared electrodes for the simultaneous determination of AA, DA and UA were systematically investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and demonstrated three well-resolved oxidation peaks for the aforementioned analytes. Under optimum conditions, the 3DGH-AuNPs/GCE exhibits linear responses to AA, DA and UA in the ranges 1.0-700, 0.2-30, 1-60 M, respectively, with detection limits (S/N = 3) calculated to be 28 nM (AA), 2.6 nM (DA) and 5 nM (UA). Moreover, interference from some normally coexisting substances (like lysine, glycine, glucose, citric acid, etc) in real samples were nearly negligible. Finally, the developed sensor was successfully applied to the detection of AA, DA and UA in human serum samples with satisfactory results. The 3DGH-AuNPs nanocomposite show promising applications in the development of electrochemical sensors for chemical or biomolecules determinations. (C) 2016 Elsevier B.V. All rights reserved.