荧光相关光谱法对量子点与蛋白质结合的温度和pH依赖性的热力学研究

发布时间：2018-05-20 03:30

本文选题：荧光相关光谱 + 荧光量子点　；参考：《青岛大学》2017年硕士论文

【摘要】：由于测量具有很高的灵敏度、测量时不破坏研究体系的平衡状态以及可以进行实时监测等优点,荧光相关光谱(FCS)技术在化学、生命科学等领域得到越来越广泛的应用,特别是在生物化学领域内对原位测量显示出独有的优势。量子点由于特殊的尺寸和优异的物理化学性能,在生物化学领域吸引了越来越多的关注。当量子点被引入到蛋白质或细胞中后,它们可以被许多的蛋白质包覆而形成一个蛋白质外壳,称为“蛋白质冕”。这样,被包被了蛋白质的量子点就有了更好的生物相容性,有利于量子点的生物应用和毒性研究。因此本文基于荧光相关光谱法,研究了典型的荧光纳米材料─CdSe/ZnS水溶性羧基量子点,对生物大分子的相互结合的温度和pH的依赖性,并进行了量子点与蛋白质结合的热力学分析;并且通过圆二色谱法和模拟计算得到了CdSe/ZnS水溶性羧基量子点与蛋白质之间可能的结合位点和可能的结合方式。基于荧光相关光谱技术探究了原位条件下不同基团包覆的CdSe/ZnS水溶性点与血浆和血清的结合程度,实现了在缓冲液以及纯血清和纯血液的原位环境下对FCS的应用。探究了金和银纳米颗粒对不同浓度BSA包覆的不同厚度的CdSe/ZnS水溶性羧基量子点的荧光寿命的影响,即相对作用距离对CdSe/ZnS水溶性羧基量子点的荧光寿命的影响。结果表明随着BSA对CdSe/ZnS水溶性羧基量子点的包覆厚度增大,CdSe/ZnS水溶性羧基量子点的荧光寿命都向短波长方向移动;短寿命物种的比例从14.75%增加到28.93%,长寿命物种的比例从85.25%减少到71.07%。该研究课题对于量子点的生物原位应用和毒性研究有重要意义。
[Abstract]:Because of the advantages of high sensitivity, no damage to the equilibrium state of the research system and the ability to monitor the system in real time, the fluorescence correlation spectroscopy (FCSs) technology has been widely used in the fields of chemistry, life science and so on. In particular, in the field of biochemistry, in situ measurement shows unique advantages. Quantum dots have attracted more and more attention in the field of biochemistry because of their special size and excellent physical and chemical properties. When quantum dots are introduced into proteins or cells, they can be coated with many proteins to form a protein shell called a "protein corona". In this way, the quantum dots coated by protein have better biocompatibility, which is beneficial to the biological application and toxicity study of quantum dots. Therefore, based on fluorescence correlation spectroscopy, the dependence of typical fluorescent nanomaterials, CdSe/ZnS water-soluble carboxyl quantum dots, on the binding temperature and pH of biomolecules is studied. The possible binding sites and possible binding modes between CdSe/ZnS water-soluble carboxyl quantum dots and proteins were obtained by circular dichroism and simulation. Based on fluorescence correlation spectroscopy, the binding degree of water-soluble sites of CdSe/ZnS coated with different groups to plasma and serum was investigated in situ, and the application of FCS in buffer solution, in situ environment of pure serum and pure blood was realized. The effect of gold and silver nanoparticles on the fluorescence lifetime of CdSe/ZnS water-soluble carboxyl quantum dots coated with different concentrations of BSA was investigated, that is, the influence of the relative distance of action on the fluorescence lifetime of CdSe/ZnS water-soluble carboxyl quantum dots. The results show that the fluorescence lifetime of BSA / ZnS water-soluble carboxyl quantum dots moves towards short wavelength with the increase of the coating thickness of CdSe/ZnS water-soluble carboxyl quantum dots, the proportion of short-lived species increases from 14.75% to 28.93%, and the proportion of long-lived species decreases from 85.25% to 71.07%. This research is of great significance for the biological in situ application and toxicity study of quantum dots.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.3

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