基于GR-5脱氧核酶和催化发夹组装信号放大策略的比色传感体系无酶、免标记检测Pb^(2+)  

Enzyme-free and label-free colorimetric sensing system for Pb^(2+) detection based on extended GR-5 DNAzyme and catalytic hairpin assembly(CHA)signal amplification

作　　者：喻甜凤 陈贺 郑洋 孙孟 吴继魁[1,2,3] YU Tianfeng;CHEN He;ZHENG Yang;SUN Meng;WU Jikui(College of Food Science and Technology,Shanghai Ocean University,Shanghai 201306;Shanghai Engineering Research Center of Aquatic-Product Processing&Preservation,Shanghai 201306;Laboratory of Quality and Safety Risk Assessment for Aquatic Product on Storage and Preservation(Shanghai),Ministry of Agriculture and Rural Affairs,Shanghai 201306)

机构地区：[1]上海海洋大学食品学院,上海201306 [2]上海水产品加工及贮藏工程技术研究中心,上海201306 [3]农业部水产品贮藏保鲜质量安全风险评估实验室(上海),上海201306

出　　处：《分析试验室》2022年第4期373-377,共5页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(31972772);上海自然科学基金(11ZR415400)项目资助。

摘　　要：以GR-5脱氧核酶(GR-5S)为Pb^(2+)特异性识别探针,催化发夹DNA组装技术(CHA)为信号放大策略,构建了一种新型的无酶、免标记比色检测Pb^(2+)的传感体系。Pb^(2+)的特异性识别激发GR-5E催化活性,从而对其底物(GR-5S)进行切割,释放出目标链T;T与亚稳态且含有目标识别区域的发夹H1结合而释放出部分DNA序列,该序列进一步与发夹H2杂交,形成稳定的H1-H2的复合物并释放出目标链T;目标链T进入下一个CHA循环,而H1-H2复合物一端裸露的G4-DNA序列与血红素(hemin)组装成G-四联体,进一步促进H_(2)O_(2)-ABTS催化氧化,从而产生明显的可见吸收信号。在优化实验条件下,该传感体系能够在50 min内完成Pb^(2+)检测,线性范围是1~50 nmol/L,检测限为0.03 nmol/L。该方法用于实际水样中的Pb^(2+)检测,样品加标回收率为90.8%~108.5%。Using the sequence extension GR-5 DNAzyme(GR-5 S)as the Pb^(2+) specific recognition probe,and the catalytic hairpin assembly(CHA)as the signal amplification strategy,a noval enzyme-free,label-free,and highly sensitive colorimetric sensing system for Pb^(2+) detection was constructed.The specific recognition of Pb^(2+) stimulated the catalytic activity of GR-5 E,which cleaved its substrate(GR-5 S)and released the target chain T.T binded to the metastable hairpin H_(2)O_(2) containing the target recognition region and exposed part of DNA sequence,which further hybridized with the hairpin H2 to form a stable H_(2)O_(2)-H2 complex and released the target strand T.The resultant T entered the next CHA cycle,and the G4-DNA sequence in H_(2)O_(2)-H2 complex assembled with hemin to form G-quadruplex with the catalytic activity of horseradish peroxidase.G-quadruplex further promoted the H_(2)O_(2)-mediated catalytic oxidation of the ABTS substrate,thereby generating a clear visible absorption signal.Under optimized experimental conditions,the detection system could complete the enzyme-free and label-free colorimetric detection of Pb^(2+) within 50 min,with a linear range of 1-50 nmol/L and a detection limit of 0.03 nmol/L.This method was used for detecting Pb^(2+) in actual water samples with satisfactory recovery rates of 90.8%-108.5%.

关 键 词：Pb^(2+) 脱氧核酶 催化发夹组装 无酶 

分 类 号：O657.32[理学—分析化学]