Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China; School of Chemistry and Environmental Engineering, Sichuan Provincial Academician (Expert) Workstation, Sichuan University of Science and Engineering, Sichuan, Zigong 643000, PR China.
Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
J Hazard Mater. 2017 Aug 15;336:195-201. doi: 10.1016/j.jhazmat.2017.04.039. Epub 2017 Apr 26.
A resonance Rayleigh scattering (RRS) aptasensor was fabricated for detection of Pbvia hairpin-like label-free substrate and G-wire for signal amplification. A hairpin-like DNA substrate contains a sequence in the loop labeled with ribonucleobase A and c-myc sequence in the stem. When hybridized with 8-17 DNAzyme in the presence of Pb, the sequence in the loop was activated and cleaved. Hundreds of c-myc sequences departing from the 8-17 DNAzyme yield nanowires superstructure called G-wire in the presence of Mg. The polymer G-wire was demonstrated by the RRS spectrum, polyacrylamide gel electrophoresis, and AFM. The RRS intensity was enhanced by the product G-wires, and the RRS signal at 370nm was linear with the logarithm of Pb concentration in the range of 2.0nM to 5.0μM. This method was selective for Pb even coexisting with other metal ions at high concentrations and was successfully applied to the determination of Pb in real samples. The aptasensor holds a great promise for universal RRS sensing platform for sensitive detection of various metal ions just by changing the sequence of the probe in the loop and DNAzyme.
一种共振瑞利散射（RRS）适体传感器通过发夹状无标记基底和 G 线进行信号放大来检测 Pb。发夹状 DNA 基底的环上标记有核碱基 A，茎上有 c-myc 序列。当与 Pb 存在下的 8-17 DNA 酶杂交时，环上的序列被激活并被切割。当存在 Mg 时，数百个离开 8-17 DNA 酶的 c-myc 序列会产生纳米线超结构，称为 G 线。RRS 光谱、聚丙烯酰胺凝胶电泳和 AFM 证明了聚合物 G 线的存在。RRS 强度因产物 G 线而增强，在 2.0nM 至 5.0μM 的范围内，RRS 信号在 370nm 处与 Pb 浓度的对数呈线性关系。该方法对 Pb 具有选择性，即使在高浓度共存其他金属离子时也是如此，并成功应用于实际样品中 Pb 的测定。通过改变环上探针和 DNA 酶的序列，该适体传感器有望成为通用的 RRS 传感平台，用于灵敏检测各种金属离子。
