【作者】 葛斌；

【导师】 谢青季；

【作者基本信息】 湖南师范大学 ， 分析化学， 2008， 硕士

【摘要】 生物高分子壳聚糖是甲壳素脱乙酰化反应产物,具有很好的生物兼容性、可生物降解性、成膜性和反应性,实际应用广泛。壳聚糖也常用于固定生物分子,研制酶电极等生物传感器。本学位论文中,对壳聚糖和酶电极近期研究进展进行了简要的综述,并完成了以下研究工作。1.利用壳聚糖对Cu²⁺的配位吸附作用,制得壳聚糖-Cu²⁺复合膜修饰电极,进一步通过Cu²⁺与蛋白质的配位作用将葡萄糖氧化酶固定在金电极上制得酶电极。该酶电极检测葡萄糖的线性范围为0.03～2.5 mmol L^-1,线性相关系数为0.997,检测限为1μmol L^-1（S/N=3）。以电化学石英晶体微天平（EQCM）技术监测了各修饰过程。2.在氧化条件下使对苯醌和壳聚糖的氨基发生醌胺反应,对壳聚糖进行改性,并利用改性壳聚糖固定葡萄糖氧化酶,研制了葡萄糖氧化酶电极。该酶电极检测葡萄糖的线性范围0.001～2 mmol L^-1,灵敏度为8.37μA L mmol^-1,线性相关系数为0.999。3.以戊二醛为交联剂,利用壳聚糖中氨基的活泼特性,将多巴胺连接到壳聚糖分子上,制备了电活性的壳聚糖-多巴胺复合材料及壳聚糖-多巴胺-碳纳米管复合材料。以FTIR和UV-VIS光谱对复合物进行了表征。复合物修饰Au电极能观察到邻酚的氧化还原峰,并能有效催化NADH的氧化,过电位可降低500 mV。修饰电极对NADH的检出限为65 nmol L^-1。更多还原

【Abstract】 Biopolymer chitosan（CS）is a polysaccharide derived by deacetylation of chitin,which has been widely used in scientific and industrial fields due to its excellent properties such as biocompatibility, biodegradability,ability to form films,and high reactivity.CS is usually used as a matrix to immobilize biomolecules to construct biosensors such as enzyme electrodes.In this thesis,we have briefly reviewed the recent research progress for CS and relevant enzyme electrodes,and conducted the following researches.1.A chitosan-Cu²⁺composite film modified Au electrode was prepared through the compleximetric adsorption of Cu²⁺on chitosan,and glucose oxidase was further compleximetrically adsorbed on the chitosan-Cu²⁺composite film through metal-protein complexation for fabricating an enzyme electrode.The biosensor exhibited a linear range from 0.03 to 2.5 mmol L^-1for glucose sensing,with a linear correlation coefficient of 0.997 and a detection limit of 1μmol L^-1 （S/N=3）.Various modification processes for the enzyme electrode were monitored by the electrochemical quartz crystal microbalance （EQCM）technique.2.Chitosan crosslinked by p-quinone was proposed to immobilize glucose oxidase（GOD）to develop a new GOD-based glucose biosensor.The biosensor exhibited a linear range from 0.001 to 2 mmol L^-1for glucose sensing,with a linear correlation coefficient of 0.999.3.Chitosan-dopamine and chitosan-dopamine-multiwalled carbon nanotubes composites were prepared by covalently linking the amino groups of dopamine and chitosan with glutaraldehyde,which was characterized by FTIR and UV-VIS spectra.The composite modified Au electrode with well-defined quinone redox peaks effectively mediated the oxidation of NADH in pH 7.0 phosphate buffer,with an overpotential decrease by ca.500 mV（vs.bare Au）,a limit of detection of 65 nmol L^-1.更多还原