【作者】 蔡涯文；

【导师】 韩鹤友；

【作者基本信息】 华中农业大学 ， 农药学， 2008， 硕士

【摘要】 量子点（quantum dots,QDs）是一种三维受限、近似球状的无机半导体纳米晶体,其优越的光学性质受到生物医学领域研究者的青睐。纳米金是应用极其广泛的生物标记材料,其具有制备简单、化学性质稳定、易于标记、可实现重复标记且对生物细胞无毒性等优点。本文利用光谱学方法研究水溶性量子点与纳米金的相互作用。1.通过紫外-可见吸收光谱手段对CdSe量子点与纳米金的相互作用进行研究。合成了粒径约2 nm的水溶性CdSe量子点,以及制备16 nm、19 nm和25 nm的纳米金溶胶。分别考察了反应时间、缓冲溶液的浓度、pH值、纳米金的粒径以及CdSe量子点与纳米金的浓度摩尔比等条件对相互作用的影响。结果表明:量子点与纳米金相互作用消除了纳米粒子在近紫外区的光吸收,增加在近红外区的吸收光强。在pH 7.0的磷酸盐缓冲溶液（0.02 mol/L）中,CdSe量子点与纳米金相互作用的最佳摩尔比是3100:1。2.用紫外-可见吸收光谱法和荧光光谱法对三种粒径CdTe量子点与纳米金的相互作用进行研究。在水相中合成三种粒径分别为1.94 nm,2.81 nm,3.24 nm的CdTe量子点和制备16 nm的纳米金溶胶。考察了纳米金对三种不同粒径CdTe量子点的荧光猝灭作用,通过Stern-Volmer,Lineweaver-Burk和Scatchard方程对荧光猝灭曲线进行分析校正,并用F（?）ster非辐射能量转移理论对猝灭过程进行分析,求得CdTe量子点与纳米金的结合常数、结合位点以及结合距离。结果表明,纳米金对CdTe量子点的荧光猝灭是一种静态自发的过程,猝灭效率随着量子点粒径的增加而增大。此荧光猝灭过程符合荧光共振能量转移机制。3.建立了CdTe量子点-K₃[Fe（CN）₆]化学发光新体系。研究纳米金对该化学发光体系的抑制作用,基于此对金标抗体进行检测。并探讨了CdTe量子点-K₃[Fe（CN）₆]的化学发光机理。通过考察纳米金对CdTe量子化学发光体系的作用原因,进一步研究了CdTe量子与纳米金的相互作用。更多还原

【Abstract】 Quantum dots（QDs） is a kind of inorganic semiconductor nanocrystals which is restricted in three-dimension to somewhat spherical shape.QDs is favoured in biomedicine field due to their excellent luminescence properties.Gold nanoparticles （AuNPs） is a wondrously popular biological labeling material as its prominent virtues including simple synthesis,stable chemical properties,easy labeling,repeatable and safe for organism.In this paper,the interactions between water-soluble QDs and AuNPs have been studied by spectroscopy techniques.1.Study on the interactions of CdSe QDs and AuNPs by ultraviolet-visible（UV-Vis） absorption spectra.CdSe QDs（2 nm） was synthesized in aqueous solution and AuNPs （16 nm,19 nm,25 nm） were separately prepared.Then the effects of reaction time, buffer concentration,acidity,size of AuNPs and the concentration ratio of CdSe QDs to AuNPs were investigated.The results showed that the interactions of CdSe QDs and AuNPs eliminated the near ultraviolet absorbation and enhanced the near infrared absorbation of nanoparticles.At pH 7.0 phosphate buffer solution（0.02 mol/L）,the optimal interaction molar ratio of CdSe QDs to AuNPs is about 3100:1.2.Study on the interactions of three sizes CdTe QDs and AuNPs by UV-Vis absorption spectra and fluorescence（FL） spectra.CdTe QDs（1.94 nm,2.81 nm,3.24 nm） were separately synthesized in aqueous solution and AuNPs（16 nm） was prepared.The FL quenching of three sizes CdTe QDs by AuNPs were investigated.The quenching curves were analyzed according to the modified Stern-Volmer,Lineweaver-Burk and Scatchard equations.The quenching process was analyzed by F（?）ster theory.Association constant,number of binding sites and the binding distance were calculated.It was found that the FL quenching is a static and spontaneous process.The quenching efficiency is enhancement along with the increase of CdTe QDs size.And the quenching mechanism is accord with the FL resonance energy transfer.3.A novel chemiluminescence（CL） system of CdTe QDs-K₃[Fe（CN）₆]has been developed.The CL inhibition by AuNPs was studied and AuNPs-IgG was detected by the CL system.CL mechanism was discussed.The effect mechanism of AuNPs on the CL was investigated to study the interactions between CdTe QDs and AuNPs furtherly.更多还原