▎ 摘　　要

A flexible graphene platform electrode (GPE) was prepared by transferring chemical vapor deposition graphene film from Cu foil to polyethylene terephthalate substrate with the help of polymethyl-methacrylate. L-Arginine (L-Arg) was electrodeposited on GPE to form poly(L-Arg) / GPE (P(L-Arg) / GPE) which was then characterized by scanning electron microscopy, energy dispersive spectroscopy and Raman spectroscopy. The electrocatalytic activity and enhanced conductivity of P(L-Arg) / GPE sensor was evaluated by determining xanthine (XA) in the presence of uric acid (UA) and hypoxanthine (HX) in phosphate buffer solution (PBS). The electrochemical behaviours of XA on P(L-Arg) / GPE were studied by cyclic voltammetry and differential pulse voltammetry in comparison with those on bare GPE. Further, the proposed sensor was used not only to achieve the selective determination of XA, but also to separate the voltammetric signals of UA-XA and XA-HX with potential differences of 420 and 384 mV, respectively. Under the optimized conditions, the proposed sensor displayed superb sensing property towards XA with a wide linear range from 0. 5 mu mol/ L to 140 mu mol/ L, along with a detection limit of 0. 08 mu mol/ L (S / N = 3). The P(L-Arg) / GPE was successfully applied to determine XA in human serum with good stability, reproducibility, high sensitivity, low cost as well as high resistance to interferences.