Novel electrochemical sensor using a dual-working electrode system for the simultaneous determination of glucose, uric acid and dopamine

Abstract

Dual working electrodes were constructed for the simultaneous determination of three analytes. A graphene oxide-modified glassy carbon electrode (GO/GCE) was used for adsorptive anodic stripping voltammetry to detect uric acid and dopamine, while a chitosan/glucose oxidase/Prussian blue-graphite modified glassy carbon electrode (Chi/GOx/PB-G/GCE) was used for chronoamperometric glucose detection. The fabrication and operation conditions for both electrodes were optimized. Linearity was obtained in the ranges of 0.10–30 µM and 30–80 µM for dopamine, 0.20–10 µM and 10–30 µM for uric acid and 15–1,500 µM for glucose. The system provided detection limits (LOD = 3σ/S) of 0.080 µM, 0.11 µM, and 5.7 µM for dopamine, uric acid and glucose, respectively. This dual-working electrode system showed good reproducibility and excellent recovery for the simultaneous determination of dopamine, uric acid, and glucose. When used to analyze dopamine, uric acid, and glucose in blood plasma samples, the results agreed well with those from conventional methods (P > 0.05), indicating the potential of this system to simultaneously determine these three analytes in real samples.