【作者】 印亚静；

【导师】 蔡称心；

【作者基本信息】 南京师范大学 ， 物理化学， 2006， 硕士

【摘要】 本论文较系统、深入地研究了单壁碳纳米管（SCNT）修饰电极的制作方法和电化学特性，以细胞色素c为代表，研究了血红素类蛋白质在SCNT上的固定及直接电化学性能；研究了SCNT上基于氧化酶的生物电化学传感器的制作及性能。主要内容如下： 1．研究了SCNT修饰玻碳（SCNT／GC）电极的制备方法。用扫描电镜、拉曼光谱、红外光谱等技术对SCNT进行了表征，考察了SCNT／GC电极的交流阻抗特性。实验结果表明，与裸GC电极相比，SCNT／GC电极的电化学反应电阻显著降低，表明SCNT／GC修饰电极表面的电子转移速率较快。 2．研究了细胞色素c（Cyto c）在SCNT表面的固定及直接电化学。运用吸附方法将Cyto c固定在SCNT表面；红外光谱（IR）显示被固定的Cyto c能保持原有的空间结构，没有发生变性；循环伏安测试表明，Cyto c在SCNT表面能发生稳定的直接电子转移，其i～E曲线上出现一对良好的、几乎对称的氧化还原峰；式量电位E^0’基本不随扫速的增加而变化(在20～120mV／s的扫速范围内，E^0’平均值为0.165±0.001V)。进一步的实验结果表明，吸附在SCNT表面的Cyto c仍能保持其对H₂O₂电化学还原的生物电催化活性。 3．研究了SCNT上基于葡萄糖氧化酶（GOx）生物电化学传感器的制作及性能。用Nafion将GOx固定在SCNT表面形成Nafion-GOx-SCNT／GC酶电极，用AFM和红外光谱对GOx在SCNT表面的状态进行了表征；考查了Nafion-GOx-SCNT／GC电极对β-D（+）-葡萄糖的生物电催化活性。实验结果表明，吸附在SCNT表面上的GOx没有发生变性，仍保持其对葡萄糖氧化良好的生物电催化活性。在pH=8和313K时GOx具有最佳的催化氧化效果。进一步实验结果表明Nafion-GOx-SCNT／GC电极可用来作为葡萄糖氧化酶的生物传感器，在0.5mmol／L～5.5mmol／L范围内，催化电流随浓度呈线性。更多还原

【Abstract】 This thesis investigated the fabrication and characterization of singled-walled carbon nanotube modified electrode （SCNT/GC） electrode. Extensive studies were made on the applications of the electrodes to immobilization and direct electrochemistry of heme-contained protein （Cyto c） on the surface of SCNT. The method presented here can be easily extended to immobilize and obtain the direct electrochemistry of other redox enzymes or proteins. The electrochemical biosensor based on immobilization of oxidase （glucose oxidase, GOx） on SCNT was fabrication and its performances were also characterized. The main results of this research were expressed as follows:1. A single-walled carbon nanotube modified electrode （SCNT/GC） was fabricated and characterized by techniques of scan electron microscopy （SEM）, Raman spectrum, FT-IR spectroscopy and Electrochemical impedance spectroscopy （EIS）. The results showed that the electrochemical reaction resistance of SCNT/GC electrode was much lower than that of bare GC electrode (in the systen of 5 mmol/L Fe（CN）₆^3-/4- + 0.1 mol/L KCl), indicating that the rate of the electrochemical reaction of Fe（CN）₆^3-/4- was rapid at SCNT in comparison with that at bare GC electrode.2. Cytochrome c （Cyto c） was immobilized on the surface of the single-wall carbon nanotube （SCNT） by the method of adsorption. Infrared spectroscopy indicated that Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SCNT. The direct electrochemistry of Cyto c, which was adsorbed on the surface of the SCNT, was studied by cyclic voltammetry. The voltammetric results from demonstrated that the SCNT had promotional effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H₂O₂. This modified electrode might be used in development of new biosensors and the biofuel cells.更多还原