title: Hydrothermal synthesis for high-quality glutathione-capped CdxZn1 - xSe and CdxZn1 - xSe/ZnS alloyed quantum dots and its application in Hg(II) sensing.
abstract: High-quality CdxZn1 - xSe and CdxZn1 - xSe/ZnS core/shell quantum dots (QDs) emitting in the violet-green spectral range have been successfully prepared using hydrothermal methods. The obtained aqueous CdxZn1 - xSe and CdxZn1 - xSe/ZnS QDs exhibit a tunable photoluminescence (PL) emission (from 433.5 nm to 501.2 nm) and a favorable narrow photoluminescence bandwidth [full width at half maximum (FWHM): 30-42 nm]. After coating with a ZnS shell, the quantum yield increases from 40.2% to 48.1%. These CdxZn1 - xSe and CdxZn1 - xSe/ZnS QDs were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared (FTIR) spectroscopy. To further understand the alloying mechanism, the growth kinetics of CdxZn1 - xSe were investigated through measuring the fluorescence spectra and X-ray diffraction spectra at different growth intervals. The results demonstrate that the inverted ZnSe/CdSe core/shell structure is formed initially after the injection of Cd2+. With further heating, the core/shell structured ZnSe/CdSe is transformed into alloyed CdxZn1 - xSe QDs with the diffusion of Cd2+into ZnSe matrices. With increasing the reaction temperature from 100 °C to 180 °C, the duration time of the alloying process decreases from 210 min to 20 min. In addition, the cytotoxicity of CdxZn1 - xSe and CdxZn1 - xSe/ZnS QDs were investigated. The results indicate that the as-prepared CdxZn1 - xSe/ZnS QDs have low cytotoxicity, which makes them a promising probe for cell imaging. Finally, the as-prepared CdxZn1 - xSe/ZnS QDs were utilized to ultrasensitively and selectively detect Hg2+ions with a low detection limit (1.8 nM).
authors.affiliation: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, Hubei, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Lai
authors.affiliation: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, Hubei, People's Republic of China.
authors.forename: Si-Yu
authors.initials: SY
authors.lastname: Sheng
authors.affiliation: College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, Hubei, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Mei
authors.affiliation: State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecule Sciences, Wuhan University, Wuhan, Hubei, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Zhongnan Hospital of Wuhan University, Wuhan, Hubei, People's Republic of China.
authors.forename: Qing-Lian
authors.initials: QL
authors.lastname: Guo
mesh_terms: D002104:Cadmium / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000737:chemistry* / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D008628:Mercury / Q000032:analysis*; D045663:Quantum Dots; D012643:Selenium / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013440:Sulfides / Q000737:chemistry* / Q000494:pharmacology; D013696:Temperature; D015032:Zinc / Q000737:chemistry* / Q000494:pharmacology; D017967:Zinc Compounds / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; D002104:Cadmium; D008628:Mercury; D005978:Glutathione; D012643:Selenium; D015032:Zinc; C031238:zinc sulfide
keywords: alloyed quantum dots; alloying mechanism; cytotoxicity; fluorescent sensor; hydrothermal synthesis