Hu Xue, Wang Wei, Huang Yuming
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.
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.
Talanta. 2016 Jul 1;154:409-15. doi: 10.1016/j.talanta.2016.03.095. Epub 2016 Mar 29.
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).
在本研究中，发现Hg(2+)离子可猝灭谷胱甘肽(GSH)包覆的铜簇(Cu NCs)的荧光。通过在GSH存在下简单还原CuSO4制备Cu NCs，GSH同时作为还原剂和保护剂，并通过紫外可见吸收光谱(UV-vis)、高分辨率扫描电子显微镜(HRTEM)、傅里叶变换红外光谱(FT-IR)和X射线光电子能谱仪(XPS)对其进行表征。GSH-Cu NCs尺寸小、水分散性优异、储存稳定性好、光稳定性好且在高浓度盐存在下稳定。GSH-Cu NCs具有强蓝色荧光，量子产率为10.6%，并表现出与激发无关的荧光行为。zeta电位、透射电子显微镜、共振光散射和动态光散射测量表明，Hg(2+)离子诱导的Cu NCs聚集导致了分散的Cu NCs的荧光猝灭。基于这些发现，开发了一种灵敏且选择性的荧光探针，用于检测10nM至10μM线性范围内的Hg(2+)，检测限为3.3nM(S/N=3)。所提出的方法已成功应用于测定水样和食品中的Hg(2+)含量。该方法的结果与氢化物发生原子荧光光谱法(HG-AFS)获得的结果吻合良好。
