A selective sensor based on Au nanoparticles-graphene oxide-poly(2,6-pyridinedicarboxylic acid) composite for simultaneous electrochemical determination of ascorbic acid, dopamine, and uric acid

Abstract

A new strategy based on gold nanoparticles (AuNPs), poly(2,6-pyridinedicarboxylic acid) (P(PDA)), and a graphene oxide (GO)-modified glassy carbon electrode (GCE/AuNPs/P(PDA)-GO) for the simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) was proposed in this study. The composite electrode was characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The GCE/AuNPs/P(PDA)/GO exhibited good electrochemical behavior towards the electrocatalysis of AA, DA, and UA due to the synergistic effects between P(PDA), GO, and AuNPs. The electro-oxidation signals appeared as three clearly seperated peaks with remarkable peak potential differences of 0.161 V (AA–DA), 0.336 V (AA–UA), and 0.175 V (DA–UA). The linear responses of AA, DA, and UA were in the concentration ranges of 6.0 to 2400.0, 0.05 to 100.0, and 0.5 to 150.0 µmol L‒1 with the detection limits of 1.764, 0.017, and 0.160 µmol L‒1, respectively. The sensor was used for the voltammetric determination of AA, DA, and UA in human urine samples using the standard addition method with satisfactory results.