固定蓝多铜氧化酶纳米复合物修饰电极的电化学行为研究

发布时间：2018-03-13 03:03

本文选题：蓝多铜氧化酶　切入点：直接电子迁移　出处：《新疆师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：蓝多铜氧化酶作为酶燃料电池阴极和酶电化学传感器的电催化剂近年来得到了广泛的应用,但一些缺陷限制了它在工业生产中的进一步应用,例如酶基电子器件制备工序复杂,力学、热稳定性以及抗干扰性差等。更重要的是载体上固定酶分子难以实现其活性中心与导电基体之间的有效电子导通。针对上述问题,本文选择几种含有疏水芳环或芳杂环以及含键合基团的分子(芳族化合物作为单体聚合得到的导电聚合物,壳聚糖的衍生物以及含双重键合基团的芳族化合物)与纳米材料复合的方式制备固酶载体,利用固酶载体与酶分子间的化学偶联,配位络合以及物理吸附等相互作用的协同效应,使得蛋白质分子以特定取向或是随机排列在载体表面。本论文使用电化学和光谱学方法研究和评估了载体表面固定酶-导电基体间的直接电化学,固酶电极对特定底物的催化性能以及酶-载体间相互作用对酶催化性能的影响,并评估了这些电极对特定底物的传感性能。1以芳环功能化纳米金粒子和壳聚糖衍生物混合所得复合物作为固酶载体,利用前述协同效应,不但能使酶分子采取特定排列形式固载于固酶载体表面,具有良好的力学稳定性,还促进了酶电极间的直接电子迁移。并评估了该纳米复合物固定漆酶基电极对儿茶酚的传感性能。基于固定漆酶纳米复合物的儿茶酚电化学传感器拥有灵敏度高,对底物特异选择性和低检测限的优势,而且这种传感器检测儿茶酚不受到共存氧分子的干扰。2以聚苯胺-草酸钴(CoC_2O_4)作为固定酶载体,制备得到蓝多铜氧化酶基电极,研究了该固酶电极的直接电化学以及催化氧还原性能。实验结果表明:该固酶电极在不含电子介体的溶液中可以实现酶活性中心T2与导电基体之间的直接电子迁移,而且可以有效地催化氧还原,但催化反应受制于酶吸附氧分子形成的中间产物分解为水分子的过程。3采用羧甲基壳聚糖化学偶联磁性四氧化三铁磁性纳米粒子作为固酶载体,制备了固定漆酶基电极,研究了这种固酶电极的有效电子迁移和催化氧还原性能。实验结果表明:只是单纯依靠酶-载体间化学偶联使酶分子随机分布在载体表面的磁性纳米粒子固酶电极,只有加入电子介体才能得以实现酶-电极间的有效电子迁移和有效催化氧还原,其催化氧还原反应的决速步是电子介体的扩散过程。
[Abstract]:Blue polycopper oxidase has been widely used as an electrocatalyst for enzyme fuel cell cathodes and enzyme electrochemical sensors in recent years, but some defects limit its further application in industrial production, such as the complex preparation process of enzyme based electronic devices. Mechanics, thermal stability and poor anti-interference. More importantly, it is difficult for immobilized enzyme molecules on the carrier to realize effective electronic conduction between their active center and conductive matrix. In this paper, several kinds of molecules containing hydrophobic aromatic rings or aromatic heterocycles and containing bonding groups (aromatic compounds) were selected as conductive polymers by monomer polymerization. Chitosan derivatives and aromatic compounds containing double binding groups) were used to prepare immobilized enzyme carriers by combining with nanomaterials, and the immobilized enzyme carriers were chemically coupled with enzyme molecules. The synergistic effects of coordination complexation and physical adsorption. In this paper, electrochemical and spectroscopic methods were used to study and evaluate the direct electrochemistry between the immobilized enzyme and conductive matrix on the surface of the carrier. The catalytic activity of solid enzyme electrode to specific substrate and the effect of enzyme carrier interaction on enzyme catalytic performance. The sensing performance of these electrodes to specific substrates was also evaluated. 1. The complexes of aromatic ring functionalized gold nanoparticles and chitosan derivatives were used as carriers for enzyme fixation, and the synergistic effects were utilized. Not only can the enzyme molecules be immobilized on the surface of the enzyme carrier in a specific arrangement form, but also have good mechanical stability. It also promoted the direct electron transport between enzyme electrodes, and evaluated the sensing performance of the nano-complex immobilized laccase based electrode to catechol. The electrochemical sensor of catechol based on the immobilized laccase nanocomplex has high sensitivity. The biosensor was not interfered by coexisting oxygen molecules. 2. Polyaniline-Cobalt oxalate CoC2O4) was used as the carrier of the enzyme to prepare the blue polycopper oxidase electrode. The direct electrochemistry and catalytic oxygen reduction of the electrode were studied. The experimental results show that the direct electron transfer between the enzyme active center T2 and the conductive matrix can be realized in the solution without electron medium. Moreover, oxygen reduction can be effectively catalyzed, but the catalytic reaction is restricted by the process of decomposing the intermediate products formed by enzyme adsorbing oxygen molecules into water molecules. 3. 3. Carboxymethyl chitosan chemically coupled magnetic ferromagnetic nanoparticles are used as solid enzyme carriers. Immobilized laccase based electrodes were prepared. The effective electron transport and catalytic oxygen reduction properties of this kind of enzyme electrode were studied. The results showed that the magnetic nanoparticles immobilized enzyme electrode was only dependent on the chemical coupling between the enzyme and the carrier to make the enzyme molecule distribute randomly on the surface of the carrier. Only the addition of electronic medium can realize the effective electron transfer between enzyme and electrode and the effective catalytic oxygen reduction. The fast step of the catalytic oxygen reduction is the diffusion process of the electron medium.
【学位授予单位】：新疆师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.1

【参考文献】