Water-soluble zinc-blende CuInS 2 and CuInS 2 / ZnS core-shell quantum dot structure and preparation method

The invention relates to CuInS2 quantum dots with a water-soluble zinc blende structure, CuInS2/ZnS core shell quantum dots with a water-soluble zinc blende structure and a preparation method thereof. In the CuInS2 quantum dots with the water-soluble zinc blende structure, the atomic ratio of Cu to In to S is 1.17 to 1 to 2.62, the XRD pattern of the CuInS2 quantum dots has three main structural characteristic peaks comprising 28.61 DEG, 47.51 DEG and 55.81 DEG which are corresponding to (111), (220) and (222) in the zinc blende crystal structure. The range of fluorescence-emission peak position of the CuInS2/ZnS core shell quantum dots with the water-soluble zinc blende structure is 554-710 nm, and the fluorescence quantum yield is 15-30 %, so that the biomedical diagnostic requirements are satisfied. The method combines the popular and mature colloid chemistry synthesis method for preparing oil soluble quantum dots at present, the CuInS2 quantum dots with the water-soluble zinc blende structure and CuInS2/ZnS core shell quantum dots with the water-soluble zinc blende structure are prepared by using PEG as solvent, sulfhydryl undecanoic acid as ligand and sulfur source, so that the step of biocompatibility modification is saved for later biomedical diagnosis. The quantum dots and the preparation method disclosed in invention have the advantages of short synthesis cycle, simple technology and good repeatability, and are beneficial to the mass production.