Zhao Xu-Hua, Gong Liang, Wu Yuan, Zhang Xiao-Bing, Xie Jun
Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Talanta. 2016;149:98-102. doi: 10.1016/j.talanta.2015.11.038. Epub 2015 Nov 17.
In this work we use a water-soluble cationic perylene derivative (compound 1) as the G-quadruplex (G4) structure fluorescence indicator to construct a fluorescent biosensor for simple, rapid and label-free detection of Pb(2+). In the absence of Pb(2+), strong electrostatic interactions between compound 1 and the G-rich DNA probe (PW17) induced the aggregation of compound 1 and resulted in the fluorescence quenching. In the presence of Pb(2+), the PW17 formed Pb(2+)-stabilized G4 structure, which reduced the aggregation of compound 1 and gave rise to high fluorescence. This allowed us to use convenient "mix-and-detect" protocol for quantitative analysis of Pb(2+). Since Pb(2+) can specially induce PW17 to form compact DNA fold, our proposed biosensor displayed high selectivity for Pb(2+). It also exhibited a high sensitivity to Pb(2+), with a limit of detection of 5.0nM observed. Furthermore, the biosensor was applied for the detection of Pb(2+) in urine and paint samples, and both showed satisfactory results.
在这项工作中，我们使用一种水溶性阳离子苝衍生物（化合物1）作为G-四链体（G4）结构荧光指示剂，构建了一种用于简单、快速且无标记检测Pb(2+)的荧光生物传感器。在不存在Pb(2+)的情况下，化合物1与富含G的DNA探针（PW17）之间的强静电相互作用诱导了化合物1的聚集，导致荧光猝灭。在存在Pb(2+)的情况下，PW17形成了由Pb(2+)稳定的G4结构，这减少了化合物1的聚集并产生高荧光。这使我们能够使用便捷的“混合检测”方案对Pb(2+)进行定量分析。由于Pb(2+)能够特异性地诱导PW17形成紧密的DNA折叠结构，我们提出的生物传感器对Pb(2+)表现出高选择性。它对Pb(2+)也具有高灵敏度，观察到的检测限为5.0 nM。此外，该生物传感器应用于尿液和油漆样品中Pb(2+)的检测，两者均显示出令人满意的结果。
