Synthesis Of CdSe/CdS Core/shell Quantum Dots And Fluorescent Microspheres And The Study On Their Application

This thesis describes current approaches for the synthesis ofâ…¡-â…£semiconductor nanoparticles, the soluble modification on its surface and their applications on life science research. CdSe and CdSe/CdS(core/shell structure) nanoparticles were synthesized both in aqueous solution by using sodium citrate as the stabilizer and microemulsion method by using SDS/isopentanol/cyclohexane/water microemulsion system. After gained nanoparticles with good luminescent property, a new approach was developed for making luminescent microsphere. Furthermore, the polylysine microsphere were successfully used to the liver cells labelling.The main content in this thesis : (1) The pridine-capped CdSe nanoparticle was prepared in microemulsion solution, Various reaction conditions that affected the optical properties of CdSe and CdSe/CdS nanoparticles were studied, including the time of reaction, the concentration of the reactants, the reactant's proportion and the dosage of isopentanol and water. Furthermore, these nanoparticles were characterized by High resolution electron microscopy, fluorescence spectra and UV-Vis spectroscopy, the UV-Vis spectroscopy provide information about the progress of nucleation and growth of the particles. Meanwhile, the fluorescent intensity of the refluxed particle was also detected. (2) CdSe and CdSe/CdS nanoparitcles were synthesized in aqueous solution by using sodium citrate as stabilizer. They were characterized by UV-Vis, fluorescence spectroscopy. (3) Based on the above work, Polylysine was used as template and the sodium citrate stabilized nanoparticles were incorporated into the microspheres. Different influence factors were studied, including the stability that the nanoparticles that dispersed in different medium and time and their fluorescent intensity were also detected. Under laser confocal microscopy, it's clearly to see that the luminescent quantum dots was well-proportioned in the microsphere. The stability of the microsphere waas also examined and results shows that the microspheres were very stable. So, we developed a new one-step approach preparing stable luminescent microsphere. Comparing with traditional methods, this method was more simple, while majority nanoparticle was enwrapped in the polylysine microsphere and no leakage was detected. It's produced less contamination and more environmental compatible. When the microspheres was co-cultured with liver cancer cell (SMMC-7721), the cell can swallow these micro-sized sphere. After modified the...