Bioconjugation Of CdTe/CdS Quantum Dots With Proteins And Their Bio-Applications

In this thesis, we explored the feasibility for biological application of water-soluble CdTe/CdS quantum dots (QDs) as a novel fluorescent probe. The work mainly included the Synthesis of CdTe/CdS QDs in aqueous phase; the bioconjugation between CdTe/CdS QDs and proteins; the characterization of the CdTe/CdS QDs-protein conjugates, and the specific cell imaging of targets EGFR on the membrane using the direct immunofluorescence method.In our experiment, The CdTe/CdS QDs were prepared, and had high QY and good stability. In the bio-conjugation, we investigated the concentrations of QDs, proteins, and the reaction time systematically. we found that luminescent CdTe/CdS QDs prepared in aqueous phase very facilely conjugated to antibodies based on their strong adsorption. Experiments with CE-LIF, fluorescence spectrometry and FCS documented that the QDs conjugates with antibody possessed high fluorescence, small hydrodynamic radii and good stability in aqueous solution. We also tested some other antibodies and found that CdTe/CdS QDs also strongly adsorbed to these antibodies like EGFR antibody.In cell imaging, we developed an integrative method to specifically label targets in live cancer cells using QDs as fluorescent probes and discussed the potential application values for the luminescent CdTe/CdS QDs prepared in aqueous phase. Our results presented that the QD probe with EGFR antibody was able to specifically bind the corresponding cellular membrane target EGFR; Our preliminary results illustrated that CdTe/CdS QDs prepared in water phase probably will become an attractive alternative probes in cellular imaging and bio-labeling.