基于L-半胱氨酸功能化的MoS_2荧光量子点检测Hg^(2+)

Fluorescence Detection of Hg^(2+) Based on L-Cysteine Functionalized MoS_2 Quantum Dots

本文采用水热法,以Na_2MoO_4为钼源,L-半胱氨酸作为硫源及稳定剂,合成荧光二硫化钼量子点(MoS2QDs),利用紫外-可见光谱、荧光光谱和红外光谱对量子点的结构和性能进行了表征。所合成MoS2QDs呈现较强蓝色荧光的性能,并具有较好的分散性。MoS_2QDs作为探针与Hg^(2+)作用后产生荧光猝灭现象,由此建立了一种测定Hg^(2+)的荧光分析新方法。该方法对Hg^(2+)测定的线性范围是5.0×10-7~2.0×10-4 mol/L,检测限为2.3×10-7 mol/L,相关系数为0.998。该方法具有操作简单、灵敏度高和选择性好等特点,可用于自来水水样中痕量Hg^(2+)的测定。

MoS2 quantum dots （MoS2 QDs） were prepared using sodium molybdate and L-cysteine as precursors through a facile hydrothermal route. The chemical structure and properties of as-prepared MoS2 QDs were characterized using UV-Vis, fluorescence and FT-IR spectra. The MoS2 QDs exhibited strong blue fluorescence and good water dispersity. The fluorescence of MoS2 QDs was quenched with the addition of Hg2＋. Thus, an analytical method was developed for fluorescence detection of Hg2＋. This method showed a wide linear range for concentration of Hg2＋ from 5.0X 10-7 to 2.0X 10.4 mol/L with a detection limit of 2.3 ）〈 10.7 mol/L. This method also possessed some advantages such as easy operation, high sensitivity and selectivity,which can be applied to the detection of Hg2＋ in tap water.