▎ 摘　　要

Nitrogen-doped graphene (NG) was used to modify a glassy carbon electrode (GCE), which was applied to the voltammetric detection of uric acid (UA). Because of the presence of NG on the GCE surface, the modified electrode showed excellent electrocatalytic ability for UA oxidation with increase of the peak current and decrease of the peak potential. Compared to that of the traditional GCE, the overpotential of the oxidation peak decreased by 50 mV. Electrochemical performance of UA was studied on NG/GCE in detail, which showed a quasi-reversible, diffusional-controlled process. Electrochemical parameters including the charge transfer coefficient (a), the number of electron transfer (n), and the diffusional coefficient (D) were calculated. At the optimal conditions, the oxidation peak current was linear, with UA concentration from 0.1 to 10.0 mu mol/L as revealed by differential pulse voltammetry, and the detection limit was estimated as 0.042 mu mol/L (3s). The UA content in the urine sample of a healthy volunteer was determined by the proposed method with a recovery of 98.7-102.3%.