纳米金和CdTe量子点体系作用机制研究
发布时间：2018-08-09 15:20
【摘要】：能量转移在生物成像、光伏元件、光信号传感器等方面有着广泛的应用。在传统的FRET体系中,能量供体和受体都是有机分子,这限制了FRET的应用。近年来,量子点以其独特的物理化学性质代替有机分子成为新型能量供体,使量子点为基础的生物传感器应运而生。同时,纳米金作为一种高效率的能量受体也代替了有机分子受体,因而基于量子点-纳米金体系的荧光共振能量转移体系备受关注。FRET的能量转移效率受到多方面因素的影响,比如说纳米粒子的大小、形貌以及供体和受体之间的距离等,而对该体系的荧光共振能量转移机制研究甚少。因此纳米金和CdTe量子点相互作用机制是本文研究的重点。本论文以CdTe量子点为能量供体,以不同粒径纳米金为能量受体构建荧光共振能量转移体系。运用光谱法探究了两者之间的相互作用,通过分析荧光光谱数据得到了研究体系的猝灭常数和能量转移效率,并详细讨论了纳米金粒径对能量转移效率的影响和两者相互作用的机制。另外,化学修饰方法分别将NH2-DNA和SH-DNA连接在CdTe量子点纳米金的表面,通过两条DNA的互补配对,实现供体和受体之间的荧光共振能量转移。根据荧光光谱数据和F?rster荧光共振能量转移理论,得出该体系的猝灭常数和能量转移效率,讨论了纳米金粒径对该体系能量转移效率的影响以及两者之间作用机制。研究表明,供体和受体均修饰的体系其猝灭常数要大于未修饰体系。而且表面修饰体系的猝灭效率是随着纳米金粒径的增加出现最大值,即先增加后减小,而未修饰体系的猝灭效率是随着纳米金粒径的增加而增加,最后达到一个平台。本文的研究结果对基于纳米金-CdTe量子点体系在生物传感器的发展有一定的理论指导意义。
[Abstract]:Energy transfer is widely used in biological imaging, photovoltaic elements, optical signal sensors and so on. In traditional FRET systems, both energy donors and receptors are organic molecules, which limits the application of FRET. In recent years, quantum dots (QDs) have replaced organic molecules as new energy donors by their unique physical and chemical properties, which make quantum dots based biosensor come into being. At the same time, as a kind of high efficient energy receptor, nanocrystalline gold also replaces the organic molecule receptor. Therefore, the fluorescence resonance energy transfer system based on quantum dot-nanocrystalline gold system has attracted much attention. The energy transfer efficiency of FRET is affected by many factors. For example, the size, morphology and distance between the donor and the acceptor of the nanoparticles, but the fluorescence resonance energy transfer mechanism of the system is rarely studied. Therefore, the interaction mechanism between gold nanoparticles and CdTe quantum dots is the focus of this paper. In this paper, CdTe quantum dots were used as energy donors and gold nanoparticles with different particle sizes as energy receptors to construct fluorescence resonance energy transfer system. The interaction between the two was investigated by means of spectral method. The quenching constants and energy transfer efficiency of the study system were obtained by analyzing the fluorescence spectrum data. The effect of gold nanoparticles on the energy transfer efficiency and the mechanism of their interaction are discussed in detail. In addition, NH2-DNA and SH-DNA were connected to the surface of CdTe quantum dot nanocrystalline gold by chemical modification, and the fluorescence resonance energy transfer between donor and acceptor was realized by complementary pairing of two DNA. Based on the fluorescence spectrum data and F?rster resonance energy transfer theory, the quenching constant and energy transfer efficiency of the system are obtained. The effect of gold nanoparticles on the energy transfer efficiency and the mechanism between them are discussed. It was found that the quenching constants of donor and acceptor modified system were higher than that of unmodified system. Moreover, the quenching efficiency of the surface modification system is the maximum with the increase of the particle size of gold nanoparticles, that is to say, the quenching efficiency of the unmodified system increases first and then decreases, while the quenching efficiency of the unmodified system increases with the increase of the particle size of gold nanoparticles, and finally reaches a platform. The results of this paper have some theoretical significance for the development of biosensor based on nanocrystalline au CdTe quantum dot system.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
本文编号：2174505
[Abstract]:Energy transfer is widely used in biological imaging, photovoltaic elements, optical signal sensors and so on. In traditional FRET systems, both energy donors and receptors are organic molecules, which limits the application of FRET. In recent years, quantum dots (QDs) have replaced organic molecules as new energy donors by their unique physical and chemical properties, which make quantum dots based biosensor come into being. At the same time, as a kind of high efficient energy receptor, nanocrystalline gold also replaces the organic molecule receptor. Therefore, the fluorescence resonance energy transfer system based on quantum dot-nanocrystalline gold system has attracted much attention. The energy transfer efficiency of FRET is affected by many factors. For example, the size, morphology and distance between the donor and the acceptor of the nanoparticles, but the fluorescence resonance energy transfer mechanism of the system is rarely studied. Therefore, the interaction mechanism between gold nanoparticles and CdTe quantum dots is the focus of this paper. In this paper, CdTe quantum dots were used as energy donors and gold nanoparticles with different particle sizes as energy receptors to construct fluorescence resonance energy transfer system. The interaction between the two was investigated by means of spectral method. The quenching constants and energy transfer efficiency of the study system were obtained by analyzing the fluorescence spectrum data. The effect of gold nanoparticles on the energy transfer efficiency and the mechanism of their interaction are discussed in detail. In addition, NH2-DNA and SH-DNA were connected to the surface of CdTe quantum dot nanocrystalline gold by chemical modification, and the fluorescence resonance energy transfer between donor and acceptor was realized by complementary pairing of two DNA. Based on the fluorescence spectrum data and F?rster resonance energy transfer theory, the quenching constant and energy transfer efficiency of the system are obtained. The effect of gold nanoparticles on the energy transfer efficiency and the mechanism between them are discussed. It was found that the quenching constants of donor and acceptor modified system were higher than that of unmodified system. Moreover, the quenching efficiency of the surface modification system is the maximum with the increase of the particle size of gold nanoparticles, that is to say, the quenching efficiency of the unmodified system increases first and then decreases, while the quenching efficiency of the unmodified system increases with the increase of the particle size of gold nanoparticles, and finally reaches a platform. The results of this paper have some theoretical significance for the development of biosensor based on nanocrystalline au CdTe quantum dot system.
【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
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