A simple and selective method for the determination of silver ions was developed by utilizing the red- shift in emission wavelength of the core-shell CdSe/Cd5 quantum dots （QDs） functionalized with rhodanine upon th...A simple and selective method for the determination of silver ions was developed by utilizing the red- shift in emission wavelength of the core-shell CdSe/Cd5 quantum dots （QDs） functionalized with rhodanine upon the addition of Ag＋. A linear relationship was observed between the shift and the increase in concentration of Ag＋ in the range of 0.0125-12.5 μmol/L. The mechanism of the red-shift was investigated and suggested that the coordination between Ag＋ and rhodanine on the QDs surface caused an increase of particle size, which resulted in the red-shift of the QDs＇ emission wavelength. A detection limit of 2 nmol/L was achieved. The developed method showed superior selectivity and was successfully applied to the determination of silver in environmental samples.展开更多
CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic inte...CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid （TGA）. It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg^2＋. The quantitative detection of Hg^2＋ with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg^2＋ added in the range of 1-300 μg.L^-1, A detection limit of 0.56 μg.L^-1 was achieved. The sensor showed superior selectivity for Hg^2＋ and was successfully applied to the determination of mercury in environmental samples with satisfactory results展开更多
基金The National Natural Science Foundation of China is thanked for financial support(Nos.20345006 and 20575043)
文摘A simple and selective method for the determination of silver ions was developed by utilizing the red- shift in emission wavelength of the core-shell CdSe/Cd5 quantum dots （QDs） functionalized with rhodanine upon the addition of Ag＋. A linear relationship was observed between the shift and the increase in concentration of Ag＋ in the range of 0.0125-12.5 μmol/L. The mechanism of the red-shift was investigated and suggested that the coordination between Ag＋ and rhodanine on the QDs surface caused an increase of particle size, which resulted in the red-shift of the QDs＇ emission wavelength. A detection limit of 2 nmol/L was achieved. The developed method showed superior selectivity and was successfully applied to the determination of silver in environmental samples.
基金the financial support from the National Natural Science Foundation of China (Nos. 20345006 and 20575043)
文摘CdSe/CdS quantum dots （QDs） functionalized by thiourea （TU） were synthesized and used as a fluorescent sensor for mercury ion detection. The TU-functionalized QDs were prepared by bonding TU via electrostatic interaction to the core/shell CdSe/CdS QDs after capping with thioglycolic acid （TGA）. It was observed that the fluorescence of the functionalized QDs was quenched upon the addition of Hg^2＋. The quantitative detection of Hg^2＋ with this fluorescent sensor could be conducted based on the linear relationship between the extent of quenching and the concentration of Hg^2＋ added in the range of 1-300 μg.L^-1, A detection limit of 0.56 μg.L^-1 was achieved. The sensor showed superior selectivity for Hg^2＋ and was successfully applied to the determination of mercury in environmental samples with satisfactory results
