【作者】 王蕊；

【导师】 许鑫华；

【作者基本信息】 天津大学 ， 材料学， 2010， 硕士

【摘要】 电化学葡萄糖生物传感器具有选择性高、快速、简便等特点,是检测葡萄糖浓度最重要的方法。近年来,糖尿病的发病率持续增高,为了给糖尿病人提供更为高效的检测血糖手段,新型葡萄糖传感器的开发受到广泛的关注。尽管酶传感器在使用中显示了较好的选择性和灵敏性,但是酶在固定化过程中由于其内部结构稳定性不良而容易失活变性,使得传感器的稳定性不佳。可植入式实时在线监测葡萄糖传感器以及无酶葡萄糖传感器为血糖检测开辟了一条新途径。纳米材料及结构以其优异的表面效应、体积效应等多种特性,可作为电极的修饰材料,并且纳米颗粒在电极表面的吸附能力强、催化效率高、生物兼容性好,使得其修饰的电极在构建生物传感器方面有着很好的潜力。因此,本论文通过电沉积的方法在金电极表面制备了具有三维Pt-Pb“纳米花”状纳米结构,并将该修饰电极用于构建无酶葡萄糖传感器。借助扫描电镜图片,透射电镜图片和XPS谱图分析证实了三维Pt-Pb纳米花的形成。电化学测试表明,三维Pt-Pb纳米花结构修饰电极具有较大的电活性面积和高的电催化活性,同时由其构建的无酶传感器具有很好的稳定性和选择性。其对葡萄糖的检测范围是1 ~ 12 mM,选择灵敏度为10.69μA/(cm2·mM),相关系数为0.9997,最低检测限为4 mM(S/N= 3);此外,该三维Pt-Pb纳米花电极在催化葡萄糖的过程中受温度束缚性不大,响应电流随着温度的升高而增大,当增大到一定值后趋于稳定。因此,三维Pt-Pb“纳米花”修饰Au电极有望构建无酶型葡萄糖传感器,相比传统的酶电极将有更加广泛的应用。本论文首次在直径为0.35 mm的不锈钢针电极(SSN电极)表面修饰纳米Pt-Pb粒子作为固定化酶的载体,通过纳米结构试图改善针电极面积小的难题。借助对苯醌电还原过程共沉积壳聚糖(CS)/葡萄糖氧化酶(GOD)构建可植入式葡萄糖传感器。在最优的实验条件下,GOD-CS/Pt-Pb/SSN电极构建的葡萄糖传感器表现出良好的综合性能,其对底物葡萄糖的线性检测范围是0.03 ~ 9 mM,相关系数R为0.9994,选择灵敏度为0.44847μA/mM(n= 11),稳态电流响应时间约为15 s,最低检测限为0.17 mM(S/N= 3),表观米氏常数值为4.9837 mM。更多还原

【Abstract】 The electrochemical glucose biosensor is the most important method for the detection of glucose due to high selectivity, rapid response and convenience. In recent years, developing new glucose sensor was widely concerned in order to provide more effective methods of testing blood glucose for diabetics because of the increasing incidence of diabetes.Although enzyme sensor detection usually shows good selectivity and high sensitivity, the enzyme is easily denatured during its immobilization procedure because of the intrinsic stability of enzyme, which leads to the lack of stability.Therefore, the development of implantable glucose biosensor and nonenzymatic glucose biosensor is an active research area for the glucose analysis. Nanoparticles with strong adsorption capacity, fast catalytic efficiency, and good biological compatibility can be used as modified materials of electrode, because they possess lots of excellent properties, such as surface effect and volume effect. So the nanoparticles modified electrode shows promising applications for the biosensor construction. Therefore, in this paper, we reported a non-enzymatic electrochemical glucose sensor based on three-dimensional Pt-Pb flower-like nanostructures which were synthesized by electrochemical deposition. SEM images, TEM images and XPS results confirmed the formation of 3D Pt-Pb nanoflower nanostructures. The electrochemical tests showed that the Pt-Pb nanoflower-like particles modified electrode possess a large electroactive surface area and high electrocatalysis activity. Meanwhile, the non-enzyme biosensor constructed by it has a good stability and selectivity. The linear detection range of glucose was from 1 to 12 mM. The response sensitiviyt is 10.69μA/mM (n= 7) with a correlation coefficient of 0.9997, the detection limitation is 4μM (S/N= 3). Moreover, this 3D Pt-Pb nanoflower electrode wasn’t serious effected by the temperature during the process of catalyzing glucose. The response current increased with a rise of temperature, and at last tend to be steady. Therefore, it will be more promising for 3D Pt-Pb nanoflowers electrode to construct non-enzyme biosensor than the traditional enzyme electrode.The present thesis was the first attempt to use a stainless steel needle electrode (SSN electrode) with a diameter of 0.35 mm as a substrate electrode. Pt-Pb nanoparticles were used to immobilizie the glucose enzyme to overcome the drawbacks of the small area of SSN electrode. A implantable glucose biosensor was constructed by codeposition chitosan (CS) / glucose oxidase (GOD) via electroreduction of benzoquinone. In the optimal experimental conditions, the sensor built by GOD-CS/Pt-Pb/SSN electrode showed good integrated performances, the linear detection range of glucose was from 0.03 to 9 mM with the response sensitivity is 0.44847μA/mM (R= 0.9994, n= 11), the steady-state current response time is 15 s and detection limitation is 0.17 mM (S/N= 3), the Michaelis constant ( ) value is calculated to 4.9837 mM.更多还原