【作者】 陈红；

【导师】 康诗钊；

【作者基本信息】 华东理工大学 ， 无机化学， 2010， 硕士

【摘要】 碳纳米管具有独特的优异性质,如：良好的电子转移能力,高的长径比,大的比表面积以及强的吸附能力等。本论文就是利用其良好的性能,对其进行衍生化后,进行了一系列的研究。制备了Fe3O4纳米球修饰的的多壁碳纳米管(Fe304/MWCNTs)。然后,通过循环伏安法对Fe3O4/MWCNTs修饰电极的化学行为进行了研究,同时考察了该电极对H2O2的敏感性。结果表明,Fe3O4/MWCNTs修饰电极对H202具有很高的灵敏度,最低检测限可达到1.6×10-9mol.dm-3。其中,多壁碳纳米管的高长径比和特殊的电子结构起到了很重要的作用。这个结果表明基于碳纳米管的生物传感器具有良好的发展前景。合成了L-丙氨酸乙酯修饰的多壁碳纳米管(MWCNT-Ala),并利用傅立叶转换红外光谱对其进行了表征。通过循环伏安法对D-,L-色氨酸在MWCNT-Ala修饰电极上的电化学行为进行了探讨。同时,为了更深入地理解电化学过程的机理,分别对D,L-色氨酸在裸露的玻碳电极和MWNT-COOHs修饰电极上的电化学行为进行了考察。发现MWCNT-Ala修饰电极能够识别L／D-色氨酸的手性异构体。这主要应归因于在多壁碳纳米管上引入了手性的L-丙氨酸乙酯,而碳纳米管所起作用主要是提供了一个有效的电子通道。此外,MWNT-Ala修饰电极的选择性与溶液的pH值和扫描速率有关。结果表明在pH=6.4时,其选择性最好。并且随着扫描速率增大,其选择性也增强。通过碳纳米管与卟啉大环之间的π-π相互作用,制备了四苯基卟啉(TPP)和四苯基卟啉锌(ZnTPP)修饰的多壁碳纳米管(TPP-CNTs和ZnTPP-CNTs),并考察了其紫外、荧光以及红外光谱。利用循环伏安法、交流阻抗等手段,分别对TPP-CNTs修饰电极和ZnTPP-CNTs修饰电极的电化学行为和光电化学行为进行了研究。同时,为了为更好地探讨其机理,对碳纳米管修饰电极的电化学和光电化学行为也进行了考察。通过比较得知,TPP-CNTs中的电荷转移效率比ZnTPP-CNTs更高。一个可能的解释是,由于中心金属离子的影响,引起ZnTPP的平面性下降,卟啉分子与碳纳米管之间的π-π相互作用减弱,从而导致二者之间的电子转移效率降低。由此我们可以推测卟啉分子空间几何结构对于卟啉修饰碳纳米管中的光电子转移过程具有很大的影响。更多还原

【Abstract】 Carbon nanotubes have exceptional good properties, such as:good electron transport capability, high aspect ratio, large surface area and strong adsorption ability. We make use of their good performance to conduct a series of studies on the carbon nanotubes derivaties.The electrodes modified with multiwalled carbon nanotubes carrying Fe3O4 beads (Fe3O4/MWCNTs) were fabricated and their electrochemical behavior was investigated by cyclic voltammetry. Meanwhile, the sensitivity to H2O2 (aq) of these electrodes was also explored. The results indicated that the electrodes coated with Fe3O4/MWCNTs exhibit high sensitivity to H2O2 (aq) with a detectable concentration of 1.6×10-9 mol·dm-3, multi-wall carbon nanotubes of high aspect ratio and the special electronic structure plays a very important role, The results implied carbon nanotubes-based biosensing devices was promising for the development of biosensing devices.Alanine ethyl ester modified multi-walled carbon nanotubes (MWNT-Ala) were prepared and characterized with a Fourier transform infra-red (FT-IR) spectrometer. The electrochemical behavior of D-and L-tryptophan on the electrodes coated with MWNT-Ala was investigated by cyclic voltammetry. Meanwhile, in order to further understand the mechanism of electrochemical process, the electrochemical behavior of D-and L-tryptophan on the bare glassy carbon electrodes and the electrodes coated with multi-walled carbon nanotubes possessing carboxyl groups (MWNT-COOH) was also discussed, respectively. The results show that the electrodes coated with MWNT-Ala can recognize the L/D-tryptophan chiral isomer, which is due to the introduction of chrical alanine ethyl ester moieties on the multi-walled carbon nanotubes. Furthermore, the enantioselectivity of the electrodes coated with MWNT-Ala was studied as a function of pH of the solution and the scan rate. Its selectivity is best at pH=6.4, and with the scan rate increased, the selectivity also increased.TPP-CNTs and ZnTPP-CNTs were prepared using theπ-πinteration of porphyrin macrocycle and CNTs, and characterized with UV-vis absorption spectra, fluorescence spectra and IR. The electrochemical and photoelectrochemical behaviors of TPP-CNTs and ZnTPP-CNTs modified electrodes were investigated by cyclic voltammetry and impedance. Meanwhile, in order to understand the mechanism, the electrochemical and photoelectrochemical behaviors of CNTs modified with electrodes were also discussed respectively. The result showed that TPP-CNTs modified with electrode had better charge-transfer ability than that of the ZnTPP-CNTs modified with electrodes. This may be ascribed to the influence of the central metal ion, which leads to worse planarity. Therefore, theπ-πinteraction between porphyrin molecules and carbon nanotubes is weakened, leading to the efficiency of electron transfer lower. We can speculate the geometric structure of porphyrin molecule may play an important role in the electron transfer process of the porphyrin modified carbon nanotubes.更多还原