聚合精氨酸修饰玻碳电极在抗坏血酸存在条件下测定多巴胺

Selective determination of dopamine in the presence of ascorbic acid at the p oly-L-arginine modified electrode

这种传感器是在玻碳电极上修饰聚合精氨酸,在这种修饰电极上,多巴胺通过静电吸附聚集在电极表面,这种修饰电极对多巴胺有较强的电化学响应。在0.1mol/LPBS缓冲溶液(pH7.5)中,DA在此修饰电极(PLA/GCE)上通过脉冲伏安法所产生的在+0.158V(vs.SCE)的氧化峰,与其浓度在1.96×10-5～1.38×10-7mol/L的范围内成线性,检测限为2.0×10-8mol/L(S/N=3)。这种低成本的修饰电极简单,具有较高的灵敏度、选择性、稳定性,该法用于药剂中DA的测定,结果满意。

The sensor was prepared by modifying a glassy carbon electrode （GCE） surface with a poly - L - arginine film Dopamine could be accumulated on the L - arginine modified electrode by the electrostatic interaction. The mod- ified electrode showed strong electrocatalytic activity towards dopamin. The catalytic peak current obtained at ＋ 0. 158 V （ vs. SCE） from DPV was linearly dependent on the dopamine concentration in the range of 1.96 ×10^-5 - 1.38 ×10^-7 mol/L in the PBS buffer solution （0. 1 mol/L, pH7.5）. The detection limit （S/N = 3） was found to be 2.0×10^-8mol/L. The modified electrode showed good sensitivity, selectivity ,stability and less interference. This polymer film is considered to be a promising, low - cost, steady material in modification of electrodes.