基于DNA酶/AuNPs-GO传感器方波伏安法高灵敏检测Pb^2+  

Highly Sensitive Detection of Pb^2+ Based on DNAzyme/AuNPs-GO Sensor by Square-Wave Voltammetry

作　　者：杨瑞[1] 康天放[1] 鲁理平[1] 叶青[1] YANG Rui;KANG Tian-Fang;LU Li-Ping;YE Qing(Key Laboratory of Beijing on Regional Air Pollution Control,College of Environmental and Energy Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学区域大气复合污染防治北京市重点实验室,环境与能源工程学院,北京100124

出　　处：《分析化学》2021年第2期309-317,共9页Chinese Journal of Analytical Chemistry

基　　金：北京市科技计划项目(No.Z171100002217002);教育部博士点基金(No.20131103110011)资助。

摘　　要：制备了金纳米粒子-氧化石墨烯(AuNPs-GO)复合物,采用透射电镜(TEM)和紫外-可见吸收光谱(UV-Vis)对其进行了表征。将此复合物修饰到玻碳电极(GCE)表面,再通过Au—S键将巯基修饰的富含鸟嘌呤的DNA链(T30695)自组装到电极表面的金纳米粒子上。T30695可与Pb^2+结合形成稳定的平行G-四链体,此G-四链体再与氯化血红素(Hemin)结合形成具有过氧化物酶活性的DNA酶(DNAzyme),基于此制得Pb^2+敏感的DNA酶电化学传感器。形成的DNA酶可催化H 2O 2氧化对苯二酚(HQ),实现电化学信号的放大和Pb^2+的高灵敏检测。在优化的实验条件下,在5.0×10^-9~1.0×10^-6 mol/L浓度范围内,传感器的方波伏安(SWV)峰电流与Pb^2+浓度的对数值有良好的线性关系,检出限为1.0×10^-9 mol/L(S/N=3)。将构建的传感器用于实际水样中Pb^2+的检测,加标回收率在96%~105%之间。本传感器具有良好的重现性、稳定性和选择性。The composite of gold nanoparticles-graphene oxide(AuNPs-GO)was prepared and characterized by transmission electron microscope(TEM)and ultraviolet-visible(UV-vis)spectrophotometry,respectively.The composite was modified on the surface of a glassy carbon electrode(GCE).The mercapto-modified and guanine-rich DNA strand(T30695)was self-assembled on to gold nanoparticles on the surface of the electrode via Au—S bond.T30695 could combine with lead ions(Pb^2+)to form a stable parallel G-quadruplex.The G-quadruplex further combined with hemin to form DNAzyme with peroxidase activity.On the basis of this,a DNAzyme electrochemical sensor for Pb^2+detection was prepared.The DNAzyme could catalyze the oxidation reaction of hydrogen peroxidetowardshydroquinone(HQ)to achieve the amplification of electrochemical signal and highly sensitive detection of Pb^2+.Under the optimum conditions,the peak current of square-wave voltammetry(SWV)was linearly dependent on the logarithm of Pb 2+concentration ranging from 5.0×10^-9 mol/L to 1.0×10^-6 mol/L with a detection limit of 1.0×10^-9 mol/L(S/N=3).The recovery of Pb^2+in real water sample was 96%-105%.The sensor possessed good reproducibility,stability and selectivity to Pb^2+.

关 键 词：方波伏安法 传感器 DNA酶 铅离子(Ⅱ) 

分 类 号：O657.1[理学—分析化学] TP212[理学—化学]