發(fā)布時間：2018-08-09 15:20

【摘要】：能量轉(zhuǎn)移在生物成像、光伏元件、光信號傳感器等方面有著廣泛的應用。在傳統(tǒng)的FRET體系中,能量供體和受體都是有機分子,這限制了FRET的應用。近年來,量子點以其獨特的物理化學性質(zhì)代替有機分子成為新型能量供體,使量子點為基礎的生物傳感器應運而生。同時,納米金作為一種高效率的能量受體也代替了有機分子受體,因而基于量子點-納米金體系的熒光共振能量轉(zhuǎn)移體系備受關(guān)注。FRET的能量轉(zhuǎn)移效率受到多方面因素的影響,比如說納米粒子的大小、形貌以及供體和受體之間的距離等,而對該體系的熒光共振能量轉(zhuǎn)移機制研究甚少。因此納米金和CdTe量子點相互作用機制是本文研究的重點。本論文以CdTe量子點為能量供體,以不同粒徑納米金為能量受體構(gòu)建熒光共振能量轉(zhuǎn)移體系。運用光譜法探究了兩者之間的相互作用,通過分析熒光光譜數(shù)據(jù)得到了研究體系的猝滅常數(shù)和能量轉(zhuǎn)移效率,并詳細討論了納米金粒徑對能量轉(zhuǎn)移效率的影響和兩者相互作用的機制。另外,化學修飾方法分別將NH2-DNA和SH-DNA連接在CdTe量子點納米金的表面,通過兩條DNA的互補配對,實現(xiàn)供體和受體之間的熒光共振能量轉(zhuǎn)移。根據(jù)熒光光譜數(shù)據(jù)和F?rster熒光共振能量轉(zhuǎn)移理論,得出該體系的猝滅常數(shù)和能量轉(zhuǎn)移效率,討論了納米金粒徑對該體系能量轉(zhuǎn)移效率的影響以及兩者之間作用機制。研究表明,供體和受體均修飾的體系其猝滅常數(shù)要大于未修飾體系。而且表面修飾體系的猝滅效率是隨著納米金粒徑的增加出現(xiàn)最大值,即先增加后減小,而未修飾體系的猝滅效率是隨著納米金粒徑的增加而增加,最后達到一個平臺。本文的研究結(jié)果對基于納米金-CdTe量子點體系在生物傳感器的發(fā)展有一定的理論指導意義。
[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.
【學位授予單位】：河南師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TB383.1

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本文編號：2174505