title: Facile preparation of glutathione-stabilized gold nanoclusters for selective determination of chromium (III) and chromium (VI) in environmental water samples.
abstract: A novel method for selective determination of Cr(III) and Cr(VI) in environmental water samples was developed based on target-induced fluorescence quenching of glutathione-stabilized gold nanoclusters (GSH-Au NCs). Fluorescent GSH-Au NCs were synthesized by a one-step approach employing GSH as reducing/protecting reagent. It was found that Cr(III) and Cr(VI) showed pH-dependent fluorescence quenching capabilities for GSH-Au NCs, and thus selective determination of Cr(III) and Cr(VI) could be achieved at different pHs. Addition of EDTA was able to effectively eliminate the interferences from other metal ions, leading to a good selectivity for this method. Under optimized conditions, Cr(III) showed a linear range of 25-3800 μg L(-1) and a limit of detection (LOD) of 2.5 μg L(-1). The Cr(VI) ion demonstrated a linear range of 5-500 μg L(-1) and LOD of 0.5 μg L(-1). The run-to-run relative standard deviations (n=5) for Cr(III) and Cr(VI) were 3.9% and 2.8%, respectively. The recoveries of Cr(III) and Cr(VI) in environmental water samples were also satisfactory (76.3-116%). This method, with its simplicity, low cost, high selectivity and sensitivity, could be used as a promising tool for chromium analysis in environmental water samples.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Thanh
authors.initials: T
authors.lastname: Wang
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Yun
authors.forename: Guoliang
authors.initials: G
authors.lastname: Li
authors.forename: Jiyan
authors.initials: J
authors.lastname: Liu
authors.forename: Guibin
authors.initials: G
authors.lastname: Jiang
mesh_terms: D002857:Chromium / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry; D004784:Environmental Monitoring; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D060766:Drinking Water; D005456:Fluorescent Dyes; D002857:Chromium; D006046:Gold; D004492:Edetic Acid; D005978:Glutathione