title: Aqueous synthesis of CdTe/CdS/ZnS quantum dots and their optical and chemical properties.
abstract: In this paper, we described a strategy for synthesis of thiol-coated CdTe/CdS/ZnS (core-shell-shell) quantum dots (QDs) via aqueous synthesis approach. The synthesis conditions were systematically optimized, which included the size of CdTe core, the refluxing time and the number of monolayers and the ligands, and then the chemical and optical properties of the as-prepared products were investigated. We found that the mercaptopropionic acid (MPA)-coated CdTe/CdS/ZnS QDs presented highly photoluminescent quantum yields (PL QYs), good photostability and chemical stability, good salt tolerance and pH tolerance and favorable biocompatibility. The characterization of high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD) and fluorescence correlation spectroscopy (FCS) showed that the CdTe/CdS/ZnS QDs had good monodispersity and crystal structure. The fluorescence life time spectra demonstrated that CdTe/CdS/ZnS QDs had a longer lifetime in contrast to fluorescent dyes and CdTe QDs. Furthermore, the MPA-stabilized CdTe/CdS/ZnS QDs were applied for the imaging of cells. Compared with current synthesis methods, our synthesis approach was reproducible and simple, and the reaction conditions were mild. More importantly, our method was cost-effective, and was very suitable for large-scale synthesis of CdTe/CdS/ZnS QDs for future applications.
authors.affiliation: College of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Li
authors.forename: Chaoqing
authors.initials: C
authors.lastname: Dong
authors.forename: Lichuan
authors.initials: L
authors.lastname: Tang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhu
authors.forename: Hongjin
authors.initials: H
authors.lastname: Chen
authors.forename: Jicun
authors.initials: J
authors.lastname: Ren
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D055095:Optics and Photonics; D033362:Powder Diffraction; D012492:Salts; D013440:Sulfides / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D012492:Salts; D013440:Sulfides; D017967:Zinc Compounds; C034939:cadmium sulfide; C031238:zinc sulfide; D013691:Tellurium; C028337:cadmium telluride