Fluorescent quantum dots with high fluorescence quantum yields, fluorescence emission spectra adjustable, good biocompatibility and the stability of the optical properties of the unique advantages of narrow and symmetrical emission bands. By the surface modification can be obtained covering the functional group of the carboxyl group and an amino group, to facilitate coupling of antibodies or other biomolecules, can be used as biological probes used in biological analysis, chemical detection, and other fields of the basic research and clinical diagnosis.