基于光诱导电子转移荧光传感器检测土壤中的Hg^(2+)

A Fluorescence Sensor for the Detection of Hg^(2+) in the Soil Based on the Photoinduced Electron Transfer

基于脱氧鸟苷(G)与荧光染料发生光诱导电子转移,以及Hg2+与胸腺嘧啶(T)形成"T-Hg2+-T"结构的原理,建立一种简单、灵敏的荧光传感器检测土壤中Hg2+。实验考察了FAM标记的凝血酶适配体与其含G碱基互补DNA浓度比、互补DNA序列长度、稳定时间等因素对检测灵敏度的影响。在优化实验条件下,方法的线性范围为5.0×10-11~5.0×10-9 mol/L,检出限可达0.02nmol/L。Ca2+、Mg2+等常见阳离子对Hg2+的检测不产生干扰,方法具有良好的选择性。该传感方法无需使用有机染料或纳米材料作荧光猝灭剂,降低了实验成本,简化了操作过程。

A simple, sensitive fluorescence sensor has been established for the detection of Hg2＋ in the soil, based on the photoinduced electron transfer between deoxyguanosine（G） and fluorescent dye as well as ＂T-Hg2＋-T＇＇ structure formed by Hg2＋ specific thymine. The influence factors on detection sensitivity such as concentration ratio of FAM-labeled thrombin aptamer and its rich G base complementary DNA, different sequence length of complementary DNA, and stability time had been investigated. Under the optimal conditions,the calibration graph was linear within the range of 5.0 ;X 10-11-5. 0）〈 10-9 mol/L, with the detection limits of 0.02 nmol/L. The method shows a good selectivity for Hgz＋ , Ca2＋ , Mg2＋ and other common metal ions had no significant interferences. In this method, it is not necessary to use organic dyes or nano materials as fluorescence quenching agent,which reduces the experiment cost and simplifies the operation process.