▎ 摘　　要

Graphene nanosheets were directly electrodeposited onto a glassy carbon electrode (GCE) from the electrolyte solution containing graphene oxide (GO); the resulting electrode (ED-GO/GCE) was characterized with scanning electron microscopy. A simple and rapid electrochemical method was developed for the determination of theophylline (TP), based on the excellent properties of ED-GO film. The result indicated that ED-GO film-modified GCE exhibited efficient electrocatalytic oxidation for TP with relatively high sensitivity and stability. The electrochemical behavior of TP at ED-GO/GCE was investigated in detail. Under the optimized conditions, the oxidation peak current was proportional to the TP concentration in the range of 8.0 x 10(-7) to 6.0 x 10(-5) mol L-1 with the detection limit of 1.0 x 10(-7) mol L-1 (S/N = 3). The proposed method was successfully applied to green tea samples with satisfactory results.