【作者】 杜攀；

【导师】 蔡称心；

【作者基本信息】 南京师范大学 ， 物理化学， 2007， 硕士

【摘要】 本论文研究了单壁碳纳米管（SWNTs）快速功能化的方法及其应用。研究了1，2-萘醌修饰的SWNTs对β—烟酰胺腺嘌呤二核苷酸（NADH）电化学氧化的催化作用；研究了室温离子液体对SWNTs的修饰作用及室温离子液体／碳纳米管复合体的制备与表征，并将其应用于对血红素类蛋白质／酶直接电化学的研究；分别研究了耐尔蓝和其聚合物对SWNTs修饰及在制作基于脱氢酶传感器方面的应用。主要内容如下：1．研究了Nile Blue对SWNTs快速功能化及电催化。将NB分子修饰到SWNTs表面形成NB-SWNTs纳米复合体，谱学结果表明，NB不仅能快速、高效地修饰到SWNTs表面，而且还能有效地改善SWNTs在水溶液中的分散性能。将NB-SWNTs修饰到GC电极表面制备了NB-SWNTs／GC电极，循环伏安结果显示，其伏安曲线上不仅表现出一对良好的、几乎对称的NB单体的氧化还原峰，式量电位E^0’几乎不随扫速而变化（其平均值为（-0.422±0.002）V（vs.SCE，pH7.0））；而且还显示出NB聚合体分子的氧化还原峰，E^0’为-0.191 V（100 mV／s时）。进一步的实验结果表明，NB和SWNTs对NADH的电化学氧化具有协同催化作用，能使其氧化过电位降低多于560 mV；NB-CNT／GC电极还能较好地响应脱氢酶催化底物氧化过程中体系内NADH浓度的变化。2．研究了1，2-萘醌修饰的SWNTs对NADH电化学氧化的催化作用。将具有电活性的1，2-萘醌（1，2-naphthoquinone，Nq）分子修饰到SWNTs表面形成Nq-SWNTs纳米复合体，用紫外可见（UV-Vis）和红外光谱等方法对Nq-SWNTs进行了表征，结果表明：Nq不仅能快速、有效地修饰到SWNTs表面，而且还能有效地改善SWNTs在水溶液中的分散性能。循环伏安结果显示，与GC电极相比，SWNTs能显著提高Nq的氧化还原峰电流，其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’几乎不随扫速而变化。进一步的实验结果表明，Nq和SWNTs对NADH的电化学氧化具有协同催化作用，与SWNTs或Nq相比，Nq-SWNTs具有较高的电催化活性，能使其氧化过电位降低多于510mV。3．研究了室温离子液体对SWNTs的修饰作用，并将室温离子液体／SWNTs复合体应用于对血红素类蛋白质／酶直接电化学的研究。SWNTs分别与[bmim]BF₄和[bmim]PF₆室温离子液体（RTILs）通过研磨的方式形成亲水的[bmim]BF₄-SWNTs和疏水的[bmim]PF₆-SWNTs两种纳米复合体，用X光电子能谱、拉曼光谱、扫描电镜、紫外可见光谱等技术对两种纳米复合体进行了表征；考察了[bmim]BF₄-SWNTs修饰玻碳电极的电化学特性。循环伏安测试表明，表面带正电荷的[bmim]BF₄-SWNTs对非电中性物质的电化学参数有重要的影响。进一步的实验结果表明，血红素类氧化还原蛋白／酶在[bmim]BF₄-SWNTs修饰的玻碳电极上能表现出量化的直接电化学特性，并能保持其对氧气、过氧化氢电化学还原的电催化活性。4．研究了耐尔蓝聚合物修饰SWNTs电极的制备和性能以及在制作脱氢酶传感器方面的应用。用电化学聚合方法将Nile Blue（NB）聚合到单壁碳纳米管（SWNTs）表面形成PNb-SWNTs纳米复合体。用扫描电镜、紫外可见光谱、循环伏安法、电化学交流阻抗等方法对PNb-SWNTs纳米复合体了表征。实验结果表明，与裸GC相比，PNb-SWNTs复合物能够在较低的电位下（-80 mV）催化NADH的氧化，并可以将过电位降低多于700 mV。将酒精脱氢酶（ADH）固定到PNb-SWNTs／GC电极表面形成ADH-PNb-SWNTs／GC电化学传感器，该传感器对于乙醇的氧化具有良好的催化特性。更多还原

【Abstract】 This thesis investigated rapid functionalization of SWNTs and its applications. Extensive studies were made on electrocatalytic activities of 1,2-Naphthoquinone modified carbon nanotube toward the oxidation of NADH, on preparation and characterization of room temperature ionic liquid/single-walled carbon nanotubes nanocomposite and its application in direct electrochemistry of heme-containing proteins/enzymes, on functionalization of single-walled carbon nanotube with poly（nile blue A） and its application to dehydrogenase-based biosensor. The main results of this thesis were expressed in detail as following:1. It was reported that SWNTs was functionalized with the electroactive Nile Blue （NB）, which was a phenoxazine dye, by a method of adsorption to form a NB-SWNTs nanocomposite. The NB-SWNTs nanocomposite was characterized by several spectroscopic techniques, for example UV-Vis, FTIR, Raman spectroscopy and SEM et al., and the results showed that NB can rapidly and effectively be adsorbed on the surface of SWNTs with high stability without changing the native structure of NB and the structure properties of SWNTs. Moreover, it was shown that the dispersion ability of SWNTs in aqueous solution had a significantly improvement after SWNTs functionalized with NB even at a level of high concentration, for example 5 mg NB-SWNTs per 1 mL H₂O. The NB-SWNTs /GC electrode was fabricated by modifying NB-SWNTs nanocomposite on the GC electrode surface and its electrochemical properties were investigated by cyclic voltammetry. The cyclic voltammetric results indicated that SWNTs could improve the electrochemical behavior of NB and greatly enhance its redox peak currents. While the NB-SWNTs /GC electrode exhibited a pair of well-defined and nearly symmetrical redox peaks with the formal potential of （-0.422±0.002） V （vs. SCE, 0.1 mol/L PBS, pH 7.0）, which was almost independent on the scan rates, for electrochemical reaction of NB monomer, the redox peak potential of NB polymer located at about -0.191 V. The experimental results also demonstrated that NB and SWNTs could synergistically catalyze the electrochemically oxidation of NADH and NB- SWNTs exhibited a high performance with lowing the overpotential of more than 560 mV. The NB-SWNTs /GC electrode could effectively sense the concentration of NADH, which was produced during the process of oxidation of substrate （for example ethanol） catalyzed by dehydrogenase （for example alcohol dehydrogenase）.2. It was reported that SWNTs was functionalized with the electroactive species of Nq by a method of adsorption to form Nq-SWNTs nanocomposite. The Nq-SWNTs was characterized by spectroscopic techniques, for example UV-Vis, FTIR and SEM et al., and the results showed that Nq can rapidly and effectively be adsorbed on the surface of SWNTs with high stability. Moreover, it was shown that the dispersion ability of SWNTs in aqueous solution had a significantly improvement after SWNTs functionalized with Nq. The Nq-SWNTs /GC electrode was fabricated by modifying Nq-SWNTs nanocomposite on the GC electrode surface and its electrochemical properties were investigated by voltammetry, which indicated that SWNTs could improve the electrochemical behavior of Nq and greatly enhanced its redox peak currents. The Nq-SWNTs /GC electrode exhibited a pair of well-defined and nearly symmetrical redox peaks with the formal potential of -87.3±4.5 mV （vs. SCE, 0.1 mol/L PBS, pH 7.0）, which was almost independent on the scan rates. The experimental results also demonstrated that Nq and SWNTs could synergistically catalyze the electrochemically oxidation of NADH and Nq-SWNTs exhibited a high performance with lowing the overpotential of more than 510 mV.3. This communication describes the formation and possible electrochemical application of a novel nanocomposite based on the SWNTs and RTILs of [bmim]BF₄ and [bmim]PF₆. The nanocomposite （[bmim]BF₄-SWNTs, and [bmim]PF₆-SWNTs） was formed by simply grinding of the SWNTs with the RTILs. The results of the X-ray photoelectron spectroscopy （XPS） and Raman spectroscopy indicated that the nanocomposites were formed by adsorption of imidazolium ion on the surface of SWNTs via the "cation-π" interaction, and scanning electron microscopic （SEM） images showed that the adsorption of imidazolium ion could significantly enhance the dispersed ability of SWNTs in water and [bmim]BF₄-SWNTs （or [bmim]PF₆-SWNTs） composite could uniformly cover on the surface of glassy carbon （GC） electrode forming RTILs-SWNTs/GC modified electrode with a high stability. The modified electrodes were characterized by used to study the electrochemical impedance of two different kinds of redox couple of Fe（CN）₆^3-7Fe（CN）₆^-4 and Ru（NH₃）₆³⁺/Ru（NH₃）₆²⁺, and also to investigate the cyclic voltammetric responses of two important neutrotransmitters of dopamine （DA） and ascorbic acid （AA）. The RTILs-SWNTs composite could be readily used as a matrix to immobilization heme-containing proteins/enzymes （myoglobin, cytochrome c, and horseradish peroxidase）, and the UV-Vis spectroscopic results indicated that the proteins/enzymes retained their nature structure in the composites. The voltammetric results showed that heme-containing proteins/enzymes displayed a pair of well-defined, stable redox peak ascribing to their direct electron-transfer reaction. RTILs on the surface of SWNTs couldn’t promote the direct electron-transfer of heme-containing proteins/enzymes, but the positive charge possessing by imidazolium ion played an significantly effect on the electrochemical parameters, such as redox peak separation and the value of the formal potentials et al., of the electron-transfer reaction for non-neutral species in the studied solution. The further results demonstrated that the heme-containing proteins/enzymes entrapped in RTILs-SWNTs composites could still retain their bioelectrocatalytic activity to the reduction of oxygen and hydrogen peroxide.4. SWNTs were functionalized with poly（nile blue A） and forming a new type of nanocomposites of poly（nile blue A）-SWNTs （PNb-SWNTs） by electropolymerization of Nb monomer on the surface of SWNTs/GC electrode using cyclic voltammetry. The scanning electron microscopy （SEM）, ultraviolet-visible （UV-Vis）, cyclic voltammerty, and electrochemical impedance spectroscopy （EIS） were used to characterize the PNb-SWNTs nanocomposites. The cyclic voltammetric results indicated that PNb-SWNTs nanocomposites could catalyze the electrochemical oxidation of NADH at a very low potential （ca.（?）80 mV） and lead to a substantial decrease in the overpotential by more than 700 mV compared with bare glassy carbon （GC） electrode. A biosensor, ADH-PNb-SWNTs/GC, was developed by immobilization ADH on the PNb-SWNTs/GC electrode surface. The biosensor showed the electrocatalytic activity toward the oxidation of ethanol with a good stability, reproducibility and higher biological affinity. Under an optimal conditions, the biosensor could be used to detection ethanol, representing a typical characteristic of Michaelis-Menten kinetics with the apparent Michaelis-Menten constant of K_M^app～6.30 mM, with a linear range span the concentration of ethanol from 0.1 to 3.0 mM （with correlation coefficient of 0.998）, and the detection limit of～50μM （at a signal-to-noise ratio of 3）.更多还原