ZnO修饰铅笔芯电极电致化学发光以及对抗坏血酸的检测研究

A simple electrochemiluminescence method for detection of ascorbic acid using ZnO modifiefd pencil graphite electrode

以醋酸锌和聚乙二醇-400为原料,合成了ZnO纳米片,采用XRD和SEM等技术对其进行了表征.将ZnO滴涂在自制铅笔芯电极(PGE)表面上,制成ZnO修饰铅笔芯电极(ZnO/PGE),探究其在0.0^-1.5V电位范围内于0.1mol·L-1 NaOH溶液中的电致化学发光行为,对可能的反应机理进行了推测.基于抗坏血酸对ZnO电化学发光强度的湮灭作用,建立了一种测量抗坏血酸的新方法.抗坏血酸的浓度在2.0×10-7~8.0×10-5 mol·L-1时,发光强度和抗坏血酸浓度的对数呈线性关系,检测上限为1.0×10-7 mol·L-1.对市售维生素C片所含抗坏血酸的量进行测定,加标回收率在97.7%~107.4%.该方法具有操作简便、快速、成本较低等优点.

ZnO nanoparticles were synthesized by simple way from the raw material of acetate zinc and polyethyleneglycol(PEG-400).The samples were characterized by SEM and XRD.By dropping ZnO nanoparticles on the surface of pencil graphite electrode(PGE),A ZnO modified pencil graphite electrode(ZnO/PGE)was prepared.It was found that ZnO/PGE possess strong Electrochemiluminescence(ECL)in sodium hydroxide solution within the scanning potential range of 0.0^-1.5 V.And the related chemiluminescence mechanism of ZnO was also discussed.A new method for determining ascorbic acid was proposed based on ECL quenching of ZnO/PGE when ascorbic acid was added in the solution.A good linear relationship was shown when the concentration of ascorbic acid changed from 2.0×10-7 to 8.0×10-5 mol·L-1 with a detection limit of 1.0×10-7 mol·L-1.The ECL sensor was also successfully applied to detect vitamin C tablets with satisfactory recovery ranging from 97.7%to 107.4%.The result showed that the enumeration method was not only fast but also simple convenient characteristic.