| Semiconductor quantum dots(QDs)have attracted great interest during tile last two decades due to their unique optical properties and photochemical stability,giving rise to numerous potential applications in chemistry,physics,biology and medicine.For routine preparation,the available high-quality semiconductor quantum dots are all synthesized in nonpolar organic solvents,which are not suitable for biological application.Thus,these semiconductor quantum dots have to be further modified by appropriate hydrophilic functional groups to allow their dispersion in aqueous solutions.My dissertation is focused on the preparation,modification and primary application of high quality fluorescence quantum dots.Now,some new results are obtained from our experiments. The main results are outlined as followings:1.The synthesis of highly fluorescence CdSe/ZnS QDs modified with the gemini surfactant[C12H25N+(CH3)2(CH2)4(CH3)2N+C12H25]·2Br-(C12-4-12)via solvent evaporation method,The as-prepared water-soluble QDs presented good optical properties,their QYs were up to 40%,and they were of monodisperse and stable in water.2.Firstly,the as-prepared water-soluble CdSe/ZnS QDs could be employed for selective recognition of Cu2+and F- in aqueous media,the effect on the fluorescence intensity of QDs towards Cu2+and/or F- and the possible mechanism was discussed. Secondly,The water soluble QDs capped with gemini surfactant have been proven to be suitable for live cell imaging,the lack of cytotoxic effect is also proved by comparison with mercaptoacetic acid-modified CdSe/ZnS QDs.Finally,The gemini surfactant modified CdSe QDs shown the selective fluorescence responses between L-tyrosine(Tyr) and L-cysteine(Cys)by addition of p-sulfonatocalix[4]arene(pSCA),thus,a simple identification method of Tyr and Cys using gemini surfactant modified CdSe quantum dots by fluorescent spectroscopic technique is proposed.
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