title: Copper nanocluster-based fluorescent probe for sensitive and selective detection of Hg(2+) in water and food stuff.
abstract: In this study, Hg(2+) ions were found to quench the fluorescence of glutathione (GSH)-capped copper clusters (Cu NCs). The Cu NCs were prepared by a simple reduction of CuSO4 in the presence of GSH serving both as a reducing and protecting agents, and characterized by ultraviolet-visible absorption spectroscopy (UV-vis), high resolution scanning electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectrometer (XPS). The GSH-Cu NCs displayed a small size, excellent water-dispersibility, good storage stability, good photostability and were stable in the presence of high concentrations of salt. The GSH-Cu NCs possessed strong blue fluorescence with a quantum yield of 10.6% and exhibited an excitation-independent fluorescence behavior. The zeta potential, TEM, resonance light scattering and dynamic light scattering measurements demonstrated that the Hg(2+) ion-induced aggregation of the Cu NCs contributed to the fluorescence quenching of the dispersed Cu NCs. On these findings, a sensitive and selective fluorescent probe was developed for detecting Hg(2+) in the linear range from 10nM to 10μM with a detection limit of 3.3nM (S/N=3). The proposed method has been successfully applied to determine Hg(2+) content in water sample and food stuff. The results of the proposed method were in good agreement with those obtained by a hydride generation atomic fluorescence spectrometry (HG-AFS).
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Xue
authors.initials: X
authors.lastname: Hu
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yuminghuang2000@yahoo.com.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Huang
mesh_terms: D003300:Copper; D005456:Fluorescent Dyes; D008628:Mercury; D049329:Nanostructures; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water
chemical_list: D005456:Fluorescent Dyes; D014867:Water; D003300:Copper; D008628:Mercury
keywords: Copper nanoclusters; Fluorescence probe; Food stuff; Mercury ions