[A study of immunoassay by using quantum dots to detect Hantavirus infection].

OBJECTIVE:To develop a new method to detect anti-Hantavirus IgG antibodies (HV IgG) based on quantum dots (QDs) and indirect immune technique. METHODS:The carbodiimide crosslinking method was used to couple protein G and goat antihuman IgG on the surface of water-solubility QDs. The coverglass covered HV antigen was used as carrier, and QDs-PG-IgG conjugates was used as labeled second antibody to detect the HV-IgG in the serum samples. The detecting conditions were optimized. RESULTS:The optimum reaction time, pH and goat antihuman IgG concentration for conjugating the QDs with goat antihuman IgG were 6.0, 2h, and 20 microg/ml, respectively. The optimum working dilution of QDs-PG-IgG conjugates was 1: 200. The detection limit of the serum samples was about 1: 1280 dilution. CONCLUSION:The method established in this study has been demonstrated to be a specific, sensitive, rapid test for detecting HV antibodies, laying the foundation of single molecule detection. The anti-fluorescence quenching ability of this method was significant improved.