Simultaneous determination of dopamine, ascorbic acid and uric acid using a multi-walled carbon nanotube and reduced graphene oxide hybrid functionalized by PAMAM and Au nanoparticles

摘要

A nanohybrid based on reduced graphene oxide functionalized by poly(amido-amine), multi-walled carbon nanotubes and Au nanoparticles (RGOa€“PAMAMa€“MWCNTa€“AuNPs) for simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was reported in this paper. The RGOa€“PAMAMa€“MWCNTa€“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 RGOa€“PAMAMa€“MWCNTa€“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 ??M to 1.8 mM, 10 ??M to 0.32 mM, and 1 ??M to 0.114 mM in the co-existence systems, respectively. The corresponding detection limits are 6.7 ??M, 3.3 ??M and 0.33 ??M (S/N = 3), respectively.