石墨烯-聚乙烯吡咯烷酮复合膜修饰电极用于抗坏血酸和芦丁的同时测定

Simultaneous Determination of Ascorbic Acid and Rutin Based on Graphene-Polyvinylpyrrolidone Composite Film Modified Glassy Carbon Electrode

用聚乙烯吡咯烷酮(PVP)分散石墨烯(GR),通过滴涂法制备了石墨烯-聚乙烯吡咯烷酮复合膜修饰玻碳电极(GR-PVP/GCE),在0.05mol/L HCl溶液中,采用循环伏安法和二阶导数线性扫描伏安法研究了抗坏血酸(AA)和芦丁(Ru)在该修饰电极上的电化学行为。结果显示,GR-PVP/GCE对AA和Ru的氧化显示出高的电催化活性和良好的电分离作用,二者峰电位之差为196 mV。在最佳实验条件下,当1.0×10^(-5) mol/L Ru存在时,AA的氧化峰电流与其浓度在6.0×10^(-6)~1.0×10^(-3) mol/L范围内呈良好的线性关系,检出限为2.0×10^(-6) mol/L。而当1.0×10^(-4) mol/L AA存在时,Ru的氧化峰电流与其浓度在2.0×10^(-8)~1.0×10^(-5) mol/L和1.0×10^(-5)~8.0×10^(-5) mol/L范围内呈良好的线性关系,检出限为1.0×10^(-8) mol/L。该修饰电极可成功用于药物中AA和Ru的同时测定。

In this paper,graphene（GR）was dispersed by the use of polyvinylpyrrolidone（PVP）.Through drop-coating method the GR-PVP composite film modified glassy carbon electrode was fabricated（denoted as GR-PVP/GCE）.In 0.05 mol/L HCl solution,the electrochemical behaviors of ascorbic acid（AA）and rutin（Ru）on the modified electrode were investigated by cyclic voltametrmy（CV）and second-order derivative linear sweep voltammetry.The results indicated that the GR-PVP/GCE showed an efficient catalytic role in the electro-oxidation of AA and Ru,leading to a remarkable peak resolution（ΔEp=196 mV）between the two compounds.Under the optimal experimental conditions,the anodic peak currents were linear over ranges of 6.0×10^-6-1.0×10^-3 mol/L for AA in the presence of 1.0×10^-5 mol/L Ru and 2.0×10^-8-1.0×10^-5 mol/L and 1.0×10^-5-8.0×10^-5 mol/L for Ru in the presence of 1.0×10^-4 mol/L AA.The detection limits of AA and Ru were 2.0×10^-6 mol/L and 1.0×10^-8 mol/L respectively.The proposed method was successfully applied in the determination of AA and Ru in pharmaceutical samples.