基于核酸外切酶Ⅲ和G-四链体无标记检测Pb^2+的荧光传感器  

A label-free fluorescence sensor for the detection of Pb^2+ based on exonuclease Ⅲ and G-quadruplex

作　　者：刘萍 刘竹苗 李红艳 乔成芳 曹宝月 LIU Ping;LIU Zhumiao;LI Hongyan;QIAO Chengfang;CAO Baoyue(College of Chemical Engineering and Modern Materials,Shangluo University,Shangluo 726000;Shaanxi Key Laboratory of Tailings Comprehensive Utilization of Resources,Shangluo University,Shangluo 726000;No.1 Middle School of Houma,Linfen City,Houma 043000)

机构地区：[1]商洛学院化学工程与现代材料学院,商洛726000 [2]陕西省尾矿资源综合利用重点实验室,商洛726000 [3]山西省临汾市侯马市侯马第一中学,侯马043000

出　　处：《分析试验室》2020年第8期885-889,共5页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金项目(21703134);陕西省科技计划项目(2019JQ-249)资助。

摘　　要：基于核酸外切酶Ⅲ(ExoⅢ)的水解特性以及Pb^2+诱导富含G碱基的DNA(G-DNA)形成G-四链体结构的特点,以荧光染料SYBR GreenⅠ(SGⅠ)为信号探针,一端带有3’凸末端的线性双链DNA(G-dsDNA)为识别探针,建立了一种新型无标记检测环境样品中Pb2+的荧光传感方法。研究了不同浓度Pb^2+引起体系荧光强度变化的规律,考察了SGⅠ、ExoⅢ的浓度、溶液pH以及稳定时间等因素对检测灵敏度的影响。结果表明:在优化的实验条件下,Pb^2+浓度在2.0~50.0 nmol/L范围内与体系荧光强度的变化呈良好的线性关系,检出限为0.7 nmol/L。常见金属离子对Pb^2+的检测无明显干扰,方法具有良好的选择性。A new type of label-free fluorescence method for the detection of lead ions in environmental water was established by using fluorescent dye SYBR GreenⅠ(SGⅠ)as signal probe,and linear double-DNA(G-ds DNA)with 3’protruding at one end as recognition probe.Based on the hydrolysis characteristics of exonuclease Ⅲ and the formation of G-quadruplex structure of the DNA(G-DNA)rich in G bases induced by lead ion,the fluorescence intensity variation induced by different concentrations of Pb^2+ was investigated.The effects on the detection sensitivity were investigated such as the concentration of SGⅠ,ExoⅢ,solution pH and stability time.The results showed that there was a good linear relationship between the concentration of Pb^2+ and the fluorescence intensity of the system in the range of 2.0-50.0 nmol/L under the optimized experimental conditions.The detection limit was 0.7 nmol/L.The common metal ions had no obvious interference on the detection of Pb^2+,and the method had a good selectivity.

关 键 词：铅离子 G-四链体 核酸外切酶Ⅲ 荧光生物传感器 

分 类 号：O657.3[理学—分析化学]