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.