▎ 摘　　要

The nanocomposite of polyamidoamine (PAMAM) modified gold nanoparticles (pAuNPs)/SnO2/graphene sheets (GNs) was prepared by a new method. That is, the well dispersed AuNPs were prepared in the presence of PAMAM and resembled on the surface of 5,10,15,20-tetrakis (4-sulonatophenyl) porphyrin (H4TPPS2-) modified graphite oxide (GO) by electrostatic interaction. Then the well-distributed SnO2 was obtained from SnCl2 with the aid of GO and GO was reduced to graphene by hydrazine hydrate. The synthesized nanocomposite was characterized by Raman spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Cyclic voltammetry (CV) experiment demonstrated that the nanocomposite exhibited excellent electrochemical performance for the detection of dopamine (DA). Then the quantitative detection of DA was carried out by differential pulse voltammetry (DPV) in the presence of ascorbic acid (AA). A linear range of 0.03-10 mu M was obtained with a correlation coefficient of 0.9970. The detection limit was as low as 8 nM (S/N = 3). Moreover, the proposed method was applied for the determination of DA in real serum samples. (C) 2017 Elsevier B.V. All rights reserved.