【作者】 吕亚芬；

【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、深入地研究了多壁碳纳米管修饰电极的制作方法和电化学特性，阐明了肌红蛋白Mb、铁氧化还原蛋白、酒精脱氢酶等生物大分子在MWNT修饰电极上的直接电化学性能，探讨了它们在生物电分析中的应用，主要内容如下： 1．研究了Mb在MWNT表面的固定及直接电子转移。实验表明，Mb在MWNT／GC电极表面能进行有效、稳定的直接电子转移，其循环伏安曲线上均表现出一对良好的、几乎对称的氧化还原峰，其式量电位E^°′几乎不随扫速（至少在20～100mV／s的扫速范围内）而变化，为（-0.343±0.001）V（Vs．SCE，pH 6.9）；Mb在MWNT／GC电极表面直接电子转移的表观速率常数k_s为3.11±0.98s^-1。进一步的实验结果表明固定在MWNT／GC电极上的Mb能保持其对H₂O₂、O₂还原的生物电催化活性。 2．将来源于Spinacia Oleracea的铁氧化还原蛋白（SoFd）通过吸附的方法固定在多壁碳纳米管（MWNT）表面。紫外可见及红外光谱表明，SoFd固定在MWNT表面后没有变性。循环伏安结果表明，SoFd在MWNT表面能进行有效和稳定的直接电子转移反应，伏安曲线上表现出一对良好的、几乎对称的氧化还原峰；式量电位E^0’不随扫速（在20mV～160mV／s的扫速范围内，其平均值为-570.4±1.5mV（vs．SCE，pH 7.0））和溶液pH值的变化而变化；SoFd直接电子转移的表观速率常数k_s为0.73±0.04s^-1。 3．研究了MWNT上基于脱氢酶的生物电化学传感器的制作及性能。NADH在MWNT修饰电极上电催化氧化的峰电位约为0V，与在裸玻碳电极上相比，其过电位降低多于600mV。实验结果表明，MWNT修饰电极能很好地响应乙醇脱氢酶催化乙醇氧化时NADH浓度地变化；考察了溶液pH和温度对乙醇脱氢酶催化乙醇氧化的影响，结果表明，在pH 8和温度为308K时，乙醇脱氢酶的催化活性最好。更多还原

【Abstract】 This thesis studied the fabrication, characterization and applications of multi-walled carbon nanotube （MWNT） modified electrode. Extensive studies were made on the applications of the electrode to direct electron transfer reaction of myoglobin （Mb）, ferredoxin （SoFd）. The electrochemical biosensor based on alcohol dehydrogenase was fabrication and its performances were also characterized. The main research works are expressed as follows:1. Mb was immobilized on the surface of MWNT and the direct electron transfer reaction was studied. Cyclic voltammetric results showed a pair of well-defined redox peaks, which corresponded to the direct electron transfer of Mb, .with the formal potential (E^0’) of -0.343 ± 0.001 V （vs. SCE） in the phosphate buffer solution （pH 7.0）. The electrochemical parameters such as apparent heterogeneous electron transfer rate constant （k_s） and the value of formal potential (E^0’) were estimated. The dependence of E^0’ on solution pH indicated that the direct electron transfer reaction of Mb is coupled with proton transfer. The experimental results also demonstrated that the immobilized Mb retained its bioelectrocatalytic activity to the reduction of H₂O₂ and O₂.2. Spinacia oleracea ferredoxin （SoFd）, which was immobilize on the surface of the carbon nanotube modified glassy carbon electrode, could undergo effective and stable direct electron transfer reaction. The results of Fourier transform infrared （FTIR） spectra indicated that the procedures of immobilization SoFd on the surface of MWNT did not alter the integrate structure of SoFd or damage SoFd leading to a denatured state and SoFd retains the essential feature of its secondary structure on the surface of MWNT. The cyclic voltammetric results indicated that the SoFd-MWNT/GC electrode exhibits a pair of well-defined and nearly symmetrical更多还原