鸟嘌呤在聚L-甲硫氨酸/石墨烯修饰电极上的电化学行为及测定

Electrochemical Behaviors of Guanine on Poly(L-methionine)/Graphene Modified Electrode and Its Detection

制备了聚L-甲硫氨酸/石墨烯修饰的玻碳电极,该电极在0.1 mol/L的磷酸盐缓冲溶液（p H 7.0）中对鸟嘌呤的氧化具有明显的电催化作用。采用循环伏安法（CV）考察了p H值、扫描速率对鸟嘌呤电化学行为的影响。利用示差脉冲伏安法（DPV）对鸟嘌呤进行测定,结果表明在3.6×10-7~4.0×10-5mol/L浓度范围内鸟嘌呤的氧化峰电流与其浓度呈良好的线性关系,相关系数为0.990 4,检出限（S/N=3）为5.0×10-8mol/L。该修饰电极还具有较好的稳定性和重现性。

A poly（ L-methionine）/graphene modified glassy carbon electrode was prepared. Experiments showed that the modified electrode exhibits an obvious electrocatalytic ability for the oxidation of guanine in 0. 1 mol/L phosphate buffer solution（ p H 7. 0）. Effects of p H value and scan rate on electrochemical behaviors of guanine were investigated by cyclic voltammetry. The detection of guanine was performed by differential pulse voltammetry. The result indicated that the oxidation peak current of guanine was linear with its concentration in the range of 3. 6 × 10- 7- 4. 0 × 10- 5mol/L,with a correlation coefficient（ r） of 0. 990 4 and a detection limit（ S/N = 3） of 5. 0 × 10- 8mol/L. The modified electrode had a good stability and reproducibility.