Research Of Biological Labeling And Gene Transfection With CdTe Quantum Dots Synthesized In Water Phase

Semiconductor nanoparticles, also known as quantum dots (QDs) have attracted considerable interest in biological and medical community because of their unique size-dependent optical and electronic properties. As luminescent probes, QDs present considerable advantages over conventional organic dye molecules. However, luminescent QDs are commonly prepared by organometallic procedure and not compatible with aqueous assay conditions. Consequently, it is necessary to substitute the surface organic ligands with hydrophilic capping agents for biological applications. But for these methods, the conditions of preparation of QDs were relatively critical, and the process was complicated. In contrast, the synthesis method of QDs in an aqueous medium using thiols as stabilizing agents is of simplicity, low toxicity and low cost. Most important is ithat the stability of QDs synthesized by aqueous approach is better than that of the water-soluble QDs transformed from organic solvent. This thesis attempted to apply the QDs synthesized in aqueous solution as luminescent probes forbiological labeling.In this thesis, we introduced a method to synthesize CdTe QDs which high fluorescence density in water phase. In our study, CdTe QDS were labeling with HAS by covalence coupled action, and it is confirmed that QDS-HAS complexes had good fluorescent properties. In the second part of our study, Chitosan nanaparticles were labeled with water-souble CdTe quantum dots by electrostatic adsorption., and a novel gene vector with excellent fluorescent properties were formed. Chitosan/QDs NPs with pEGFP Cl plasmid were successfully transfected on BEL-7402 cells in vitro. In the process of gene transfection, CdTe QDS played a important role of fluorescence labeling, and this study supplied effectively in vivo fluorescence labeling tracer in the future reseacher.