Synthesis And Fluorescence Properties Of Water-soluble Doped Nanoparticles

With the improvement of synthesis of semiconductor nanoparticles(quantum dots, QDs), QDs appear many advantages as labels, when compared to existing organic dyes. This has led to practicability of the new nanotechnology. For this reason, the development of a successful synthesis of nanoparticles with good fluorescent properties is very important. This dissertation works aim to develop a synthetic method of water-soluble doped nanoparticles meeting the need of applications as biological fluorescent probes.Water-soluble doped nanoparticles(ZnS:Ag/Cys and CdS:Ag/Cys) with high luminescence have been synthesized by using L-cysteine as modifier. And CdS:Ag/ZnS/Cys nanoparticles were obtained by ZnS passivating CdS:Ag/Cys. After ZnS passivating CdS:Ag/Cys, the luminescence intensity of CdS:Ag/ZnS/Cys nanoparticles was farther higher than that of CdS:Ag/Cys nanoparticles. As these nanoparticles appear many advantages such as water-soluble, stabilization and good luminescence, they are propitious to the biological detection.In this dissertation work, the effect of calf thymus deoxyribonucleic acid (ct-DNA) on the fluorescence spectrum of the CdS:Ag/ZnS/Cys nanoparticles was also studied. The results showed that the intensity of fluorescence of the nanoparticles was quenched by ct-DNA. The CdS:Ag/ZnS/Cys nanoparticles are hopeful of being used as fluorescence probes in DNA determination.