title: Facile synthesis of high-quality water-soluble N-acetyl-L-cysteine-capped Zn(1-x)Cd(x)Se/ZnS core/shell quantum dots emitting in the violet-green spectral range.
abstract: In this paper, we report a new facile method to synthesize water-soluble Zn(1-x)Cd(x)Se and core/shell Zn(1-x)Cd(x)Se/ZnS quantum dots (QDs) emitting in the violet-green spectral range, using N-acetyl-L-cysteine (NAC) as a stabilizer. The influence of various experimental variables, including the precursor Zn/Cd/Se/NAC molar ratios, the pH of original solution and the refluxing time on optical properties were explored systematically. The obtained aqueous Zn(1-x)Cd(x)Se QDs exhibit a tunable photoluminescence (PL) emission (from approximately 415 nm to 506 nm) and a favorable narrow PL bandwidth (FWHM: 27-38 nm). After coating with a ZnS shell, the PL emission intensity of the formed core/shell Zn(1-x)Cd(x)Se/ZnS QDs is greatly increased (PL quantum yield (QY): approximately 30%). These resulting Zn(1-x)Cd(x)Se and core/shell Zn(1-x)Cd(x)Se/ZnS QDs were further characterized by transmission electron microscopy (TEM), energy disperse spectroscopy (EDS) and X-ray diffraction (XRD). In addition, the cytotoxicity and the fluorescence imaging of Zn(1-x)Cd(x)Se/ZnS QDs to MCF-7 cells were preliminarily investigated. The experimental results show that the as-prepared violet-green-emitting Zn(1-x)Cd(x)Se/ZnS QDs have low cytotoxicity, which makes them an ideal inorganic fluorescent probe for biolabeling and cell imaging.
authors.affiliation: Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cao
authors.forename: Bing
authors.initials: B
authors.lastname: Xue
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Dawei
authors.initials: D
authors.lastname: Deng
authors.forename: Yueqing
authors.initials: Y
authors.lastname: Gu
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D019187:Cadmium Compounds / Q000138:chemical synthesis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D045663:Quantum Dots; D018036:Selenium Compounds / Q000138:chemical synthesis; D013050:Spectrometry, Fluorescence; D013440:Sulfides / Q000138:chemical synthesis*; D017967:Zinc Compounds / Q000138:chemical synthesis*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C058667:cadmium selenide; C031238:zinc sulfide; D000111:Acetylcysteine