聚对苯二酚修饰电极的制备及其对抗坏血酸的催化氧化作用

Electrocatalytic Oxidation and Determination of Ascorbic Acid on Polymer Hydroquinone Modified Electrode

采用电化学方法制备聚对苯二酚薄膜修饰玻碳电极(PHQ/GCE),并用该电极对抗坏血酸(AA)进行测定.研究发现:在0.2 mol/L Na2HPO4-NaH2PO4(PBS,pH 7.0)缓冲溶液中,以0.1 mol/L KCl作支持电解质,PHQ/GCE对AA有明显的催化氧化作用.同时,应用线性扫描循环伏安法对AA进行定量分析,其氧化峰电流与AA浓度在5.0×10-6～1.0×10-1 mol/L范围内呈现良好的线性关系,检出限为1.0×10-7 mol/L.对此机理进行详细研究,结果表明聚对苯二酚修饰玻碳电极上带有的酚羟基与脱氢抗坏血酸自由基之间形成的氢键是电催化氧化的主要原因.

The polyhydroquinone film modified glassy carbon electrode（PHQ/GCE） was prepared by electrochemical method.Ascorbic acid（AA） was determined on the modified electrode.The result indicated that the film modified has good electrocatalytic ability for the oxidation of AA in 0.2 mol/L Na2HPO4-NaH2PO4（PBS,pH 7.0） solution,containing 0.1 mol/L KCl.The peak currents were proportional to the concentration of AA in the range of 5.0×10-6 ～ 1.0×10-1 mol/L with a detection limit of 1.0×10-7 mol/L.the mechanism was studied in detail. And the research showed that the hydrogen bond between AA and poly （hydroquinone） on the glassy carbon electrode （GCE） was considered to be the main reason of the electrocatalytic oxidation.