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 A mu mol L-aEuro'1 with the detection limits of 1.764, 0.017, and 0.160 A mu mol L-aEuro'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. [GRAPHICS] .