▎ 摘　　要

A nanohybrid based on reduced graphene oxide functionalized by poly(amido-amine), multi-walled carbon nanotubes and Au nanoparticles (RGO-PAMAM-MWCNT-AuNPs) for simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was reported in this paper. The RGO-PAMAM-MWCNT-AuNP-modified electrode showed a high selectivity towards the oxidation of AA, DA, and UA, and resolved their overlapped oxidation peaks into three well-defined peaks. The RGO-PAMAM- MWCNT-AuNP nanohybrids were characterized by scanning electron microscopy (SEM). Several important parameters that control the performance of the electrochemical sensor were investigated and optimized. Under optimal conditions by a differential pulse voltammetry (DPV) method, the linear response ranges for the determination of AA, DA, and UA are 20 mu M to 1.8 mM, 10 mu M to 0.32 mM, and 1 mu M to 0.114 mM in the co-existence systems, respectively. The corresponding detection limits are 6.7 mu M, 3.3 mu M and 0.33 mu M (S/N = 3), respectively.