Abstract: Objective Based on prepared and modified quantum dots, conjugated with anti Hepatitis B antibodies under EDC activation to obtain quantum dot-antibody bioconjugates. To certify its usage in immune assay. Methods High temperature decomposition are used to prepare CdSe quantum dots, and modified with GSH and PEG separately for water solubility and stability. Conjugate quantum dots and goat-anti-HBsAg polyclone antibodies with ethyl-(dimethylaminopropyl) carbodiimide (EDC). Routine immune dot blot protocol was done for the test of HbsAg antigen. Results quantum dots were produced with uniformity and stability. The HBsAg antibody can be covalently linked with quantum dots and the bioconjugates were confirmed by various characterization. The bioconjugates can be used to detect 1.6 ng HBsAg proteins by dot blot immunoassay. Conclusion The new bioconjugates of conjugation of antibodies onto quantum dots for detection of the corresponding antigens provide better amplified signal immunoassays.

Key words: Quantum dot, Anti-hepatitis B surface antigen antibody, Rapid immunoassay