水溶性功能化Ag_2S量子点的合成及其对超痕量Hg^(2+)的双模式分析应用  

Synthesis of Water-Soluble Functionalized Ag2S Quantum Dots and Dual-Mode Analytical Application for Trace Mercury Ion

作　　者：胡芹芹[1] 徐明波[1] 叶泰[1] 丁然[1] 艾永青[1] 肖虎勇[1] 张霞[1] 吕鉴泉[1] 

机构地区：[1]湖北师范学院污染物分析与资源化技术湖北省重点实验室,湖北黄石435002

出　　处：《分析科学学报》2013年第4期459-464,共6页Journal of Analytical Science

基　　金：湖北省自然科学基金重大项目(No.2010CDA061);湖北省教育厅创新团队项目和重点项目(No.D200922005);污染物分析与资源化技术湖北省重点实验室开放基金(No.KY2010M03)

摘　　要：以巯基丙酸为稳定剂,在乙二醇存在下合成了水溶性功能化Ag2S量子点。研究了该量子点的特性及其与常见金属离子的相互作用,发现仅Hg2+能够猝灭该量子点体系的荧光并使溶液变色,基于该现象建立了裸眼-荧光双模式选择性识别水体中痕量Hg2+的新方法。实验数据显示,在裸眼模式下,常见金属离子中只有Hg2+使Ag2S量子点的颜色由黄色变为无色;在荧光模式下,常见金属离子中只有Hg2+对量子点荧光猝灭最大,并且随着Hg2+浓度的增大Ag2S量子点的荧光猝灭越来越显著。研究表明,Hg2+与Ag2S量子点的作用机制可能为电荷转移致使量子点聚集而发生荧光猝灭。在优化条件下,8.0×10-9～5.6×10-8 mol/L浓度的Hg2+与Ag2S量子点荧光的猝灭呈良好的线性关系(R=0.9903),检出限(S/N=3)为4.2×10-9 mol/L,裸眼可识别9.0×10-5 mol/L的Hg2+。该方法成功地应用于水样中超痕量Hg2+的检测。. Water-soluble functionalized Ag2S quantum dots were synthesized in ethylene glycol with 3-mercaptopropionic acid as the stabilizer. The characteristics of the quantum dots were studied by fluorescence spectrometry, scanning tunneling microscopy, X-ray diffraction, infrared spectrum and thermal gravimetric analysis. The interaction of the quantum dots with common metal ions has also been investigated. The results indicated that only mercury ions changed the color of the quantum dots solution,and gave the much higher quenching efficiency to the fluorescence of Ag2S quantum dots. The studies indicated that the fluorescence of the Ag2S quantum dots was quenched by a charge transfer process between quantum dots and Hg2＋. Based on the color change and fluorescence quenching of AgzS quantum dots, a highly sensitive and selective method for the detection of trace mercury ions in water has been developed. Under the optimum condition, the calibration curve about the quenched fluorescence of AgaS quantum dots was linear in the range from 8.0 × 10-9 to 5.6 × 10-8 mol/L of the mercury ions concentration with the detection limit of 4.2 × 10-9 mol/L. 9.0 ×10-5 mol/L of mercury ions could be identified using the naked-eye method. The proposal has been successfully used for the determination of ultra trace mercury ions in water sample.

关 键 词：Ag2S量子点 双模式 Hg2+ 裸眼识别 荧光 

分 类 号：O657.3[理学—分析化学]