金纳米棒自组装体的光学性质研究及生物成像应用

发布时间：2018-08-16 18:21

【摘要】：非球形贵金属纳米粒子具有更加丰富、可调的表面等离子体共振(Surface Plasmon Resonance)行为,生物相容性较好,毒性低,以及丰富的表面可修饰性而被广泛的应用于生物方面。本论文中,我们合成了其中一类应用较为广泛的金纳米棒,研究了对其光学性质的调控及其在生物成像方面的应用。论文主要包括以下四部分:第一章为绪论。首先介绍了非球形贵金属纳米粒子,着重介绍了金纳米棒及其表面等离子体共振性质;其次,对近年来金纳米棒的合成方法进行了总结,对金纳米棒表面丰富的可修饰性进行了介绍,以及介绍了其在生物方面的应用;最后,提出了待解决的问题和潜在应用,提出本论文的工作设想;第二章研究了影响金纳米棒表面修饰二氧化硅的因素,对修饰的准确条件作了一系列考察,例如,影响二氧化硅修饰的条件包括温度、pH、时间、正硅酸乙酯(TEOS)的浓度、金纳米棒溶液中十六烷基三甲基溴化胺(CTAB)的浓度等因素,并研究了金纳米棒表面二氧化硅层厚度调节,以及继而在二氧化硅层表面修饰氨基。通过实验条件的精确调控,提高实验的重复性。第三章首次提出了通过金纳米棒的等离子体共振性质增强金纳米团簇的荧光,实现其在生物成像中的应用。以牛血清白蛋白(BSA)为配体合成的金纳米团簇具有较好的荧光性质以及良好的生物相容性,但其量子产率较低,一般介于4%到7%之间,大大的限制了其更广泛的应用。我们设计了引入金纳米棒,从而利用它的表面等离子体共振性质,以期达到提高金纳米团簇的荧光的效果,并且通过调控两者之间的距离,考察对金纳米团簇荧光的影响。实验结果表明,当金纳米棒—金纳米团簇组装体两者距离约为15 nm时(距离通过二氧化硅层调控),金纳米团簇的荧光强度增强达到最大,约为5倍;其荧光寿命与单纯的金纳米团簇相比,有所缩短。且由于所得金纳米棒—金纳米团簇组装体表面有丰富的BSA基团,不需要对其进一步修饰即可进入细胞内,最终实现了其在细胞内的双功能成像(暗场成像和荧光成像)上的应用。第四章为本论文的创新、特色之处以及工作展望。我们对已经开展的工作进行了一些总结,并对后续的研究工作进行了展望。
[Abstract]:Non-spherical noble metal nanoparticles have been widely used in biological fields due to their rich, adjustable surface plasmon resonance (Surface Plasmon Resonance) behavior, good biocompatibility, low toxicity and rich surface modifiability. In this thesis, we have synthesized one kind of gold nanorods which are widely used, and studied their optical properties and their applications in biological imaging. The thesis mainly includes the following four parts: the first chapter is the introduction. Firstly, the non-spherical noble metal nanoparticles were introduced, and the gold nanorods and their surface plasmon resonance (SPR) properties were emphasized. Secondly, the synthesis methods of gold nanorods in recent years were summarized. The surface modification of gold nanorods is introduced, and its application in biology is introduced. Finally, the problems to be solved and potential applications are put forward, and the working ideas of this paper are put forward. In the second chapter, the factors affecting the surface modification of gold nanorods were studied, and a series of accurate conditions were investigated. For example, the modification conditions include temperature, pH, time, concentration of ethyl orthosilicate (TEOS). The concentration of cetyltrimethylammonium bromide (CTAB) in gold nanorods solution was studied. The thickness adjustment of silica layer on the surface of gold nanorods and the modification of amino groups on the surface of silica layer were studied. The repeatability of the experiment is improved by the precise regulation of the experimental conditions. In chapter 3, the fluorescence enhancement of gold nanoclusters by the plasmon resonance property of gold nanorods is proposed for the first time, and the application of gold nanorods in biological imaging is realized. Gold nanoclusters synthesized with bovine serum albumin (BSA) as ligands have good fluorescence properties and good biocompatibility, but their quantum yields are generally between 4% and 7%, which greatly limits their wider application. We designed the gold nanorods to make use of their surface plasmon resonance (SPR) properties in order to improve the fluorescence of gold nanoclusters and to investigate the effect on the fluorescence of gold nanoclusters by adjusting the distance between them. The experimental results show that when the distance between gold nanorods and gold nanoclusters is about 15 nm (the distance is controlled by silica layer), the fluorescence intensity of gold nanoclusters increases to the maximum, about 5 times. Its fluorescence lifetime is shorter than that of pure gold nanoclusters. Due to the abundant BSA groups on the surface of the gold nanorods and gold nanoclusters, the gold nanorods can enter the cells without further modification. Finally, it has been applied in cell bifunctional imaging (dark field imaging and fluorescence imaging). The fourth chapter is the innovation of this paper, features and work prospects. We have carried on some summary to the work already carried out, and has carried on the prospect to the follow-up research work.
【学位授予单位】：安徽师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O614.123;TB383.1

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