石墨电极表面固定铁氰化钾的方法研究及分析应用

【作者】 刘晓山；

【导师】 郑行望；

【作者基本信息】 陕西师范大学 ， 分析化学， 2010， 硕士

【摘要】 化学修饰电极(Chemically Modified Electrode)最大的特点是在电极表面进行分子水平的修饰得到功能团化的修饰层,在电催化、分离、富集、选择性响应方面得到广泛应用。目前,化学修饰电极方法与技术的发展及其与电化学发光和电化学分析等方法的联合依然是分析化学的研究热点领域之一。本论文由综述和研究报告两部分组成。第一部分为综述,主要介绍了化学选修饰电极的原理、方法、应用,以及层层自组装技术的原理、方法其构建的电化学传感器的分析应用;第二部分为研究报告,主要利用层层自组装技术在石墨电极表面进行铁氰化钾的固定化研究,我们分别利用静电吸引制得CTAB-Fe(CN)63--CTAB修饰的石墨电极和滴涂方式壳聚糖-聚乙烯醇复合膜固定自组装铁氰化钾,构建了Fe(CN)63--ECL传感器,研究了自组装Fe(CN)63-修饰电极电化学和电化学发光行为,发展了修饰电极的材料和固定方法。具体工作包括：1.自组装CTAB-Fe(CN)63--CTAB修饰石墨电极的的制备及其分析应用研究以临界胶束浓度存在的阳离子表面活性剂CTAB能有效的附着在经煮沸石蜡处理的石墨电极表面,此时石墨电极表面带有大量的正电荷,通过自组装技术可在石墨电极表面通过静电吸引带有负电荷的铁氰化钾阴离子形成复合膜,这样,建立了一种固定铁氰化钾阴离子的复合膜的制备方法,并通过接触角、电化学和电化学发光研究了该复合膜的特性。结果表明：CTAB的长链结构增强了与充分渗透石蜡的石墨电极表面的结合能力,大大提高了单位面积内吸附Fe(CN)63-的个数,修饰电极能够展现出很好的电催化行为、电化学发光行为,提出了一种通过自组装膜固定Fe(CN)64-/3-探针的新思路。2. Chitosan-PVA-Fe(CN)6-3--CTAB复合膜修饰电极的电化学和电化学发光行为及其分析应用研究将0.5%聚乙烯醇溶液与0.5%壳聚糖溶液混合,滴涂在自组装铁氰化钾修饰电极表面,然后将电极再浸入铁氰化钾溶液中,利用壳聚糖继续吸附铁氰化钾以提高电极表面的修饰量。在最佳的实验条件下,异烟肼浓度在1.5×104-1.5×10-6 mol/L内与发光强度呈线性关系,检出限为5×10-7 mol/L。与化学发光法测异烟肼相比,该电极能重复使用,有较好的灵敏度。更多还原

【Abstract】 Chemically modified electrode is characterized by the largest molecular level in the electrode surface modification by functional groups of the modified layer, the electric catalysis, separation, enrichment, selective response been widely used. At present, the chemically modified electrode method and technology development and its electrochemical luminescence and electrochemical analysis of the joint is still one of the areas of chemical research focus.This paper by the review and study reports of two parts. the first part of review, mainly introduces chemical modify electrode of the principles, method, application, and the layers of the assembly technology of the principles, method and the electrochemical methods of analysis of the application of the sensor; The second part of the research reportt, we fixed potassium ferricyanideiron on the surface of the graphite electrode by Layers of the assembly technology and Drop-coating with the way, the Chitosan- PVA composite membrane was fixed self-assembled potassium ferricyanide modify graphite electrode, built Fe(CN)63--ECL sensors to study self-assembled Fe(CN)63- Modified Electrode and electrochemical luminescence behavior, the development of the modified electrode materials and fixation methods. Concrete work includes:1. Self-assembly of CTAB-Fe(CN)63"-CTAB Preparation of modified graphite electrode and its analytical applicationTo the existence of critical micelle concentration of cationic surfactant CTAB can effectively handle attached to the wax by boiling the surface of graphite electrode, graphite electrode surface at this time with a large amount of positive charge, through self-assembly technology in graphite electrode surface by electrostatic attraction potassium ferricyanide with a negatively charged anion form a composite membrane, so that the establishment of a fixed Ferricyanide anion composite membrane and method, and by contact angle, electrochemical and electrochemiluminescence study of the composite film characteristics. The results show that: long-chain structure of CTAB enhanced the paraffin with graphite electrodes attached to the surface adhesion,Improve the electrode surface unit area Fe(CN)63- the amount of adsorption, Modified electrode to show good electrocatalytic behavior, electrochemical luminescence behavior, A self-assembled monolayers by a fixed Fe(CN)64-/3- probe for new ways.2. Electrochemistry and Electrochemiluminescence performances of Chitosan-PVA-Fe(CN)63--CTAB composite film immobilizing and its analytical application To 0.5% Chitosan solution,0.5% PVA solution was mixed, drops on the potassium ferricyanide self-assembled modified electrode surface, and then the electrode immersed in potassium ferricyanide solution, the use of chitosan to the adsorption of potassium ferricyanide to enhance the amount of electrode surface modification. Under the optimal experimental conditions, the detection limit was 5×10-7 mol/L for isoniazid and the linear range extended from 1.5×10-4-1.5×10-6 mol/L. Compared with chemiluminescence detection isoniazid, the modified graphite electrode can used repeatedly,had better sensitivity for the determination of. isoniazid更多还原