State Key Joint Laboratory of Environmental Simulation and Pollution Control, Center for Sensor Technology of Environment and Health, School of Environment, Tsinghua University, Beijing 100084, China.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, Center for Sensor Technology of Environment and Health, School of Environment, Tsinghua University, Beijing 100084, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
J Hazard Mater. 2018 Aug 5;355:50-55. doi: 10.1016/j.jhazmat.2018.04.082. Epub 2018 May 1.
To meet the severe water pollution status, multi-target biosensor becomes one of research focus. We herein report a novel duplex functional fluorescent biosensor for the label-free and separate detection of Pb and Hg with high sensitivity and selectivity. A K-induced fluorescent G-quadruplex probe was assembled by a guanine-rich sequence (AGRO100) and N-methyl mesoporphyrin IX(NMM). It changed into a more stably non-fluorescent G-quadruplex structure and a hairpin-like structure upon binding Pb and Hg ions, respectively. As a result, the fluorescence decreased with relation to the addition of targets, allowing the separate detection of Pb and Hg ions at concentrations as low as 5 nM and 18.6 nM. The linear correlation existed between the fluorescence intensity and the concentration of Pb and Hg over the range of 10-200 nM (R = 0.98) and 20-1000 nM (R = 0.99), respectively. All real lake samples, even containing Pb or Hg at 50 nM, could be determined by the duplex functional fluorescent probe with recovery rates 96% and 104%, respectively. Considering that this sensor is label-free, simple, time-saving, cost-effective and easy-to-handle, it is possible to pave its way for Pb and Hg detection in various application fields.
为应对严峻的水污染现状，多目标生物传感器已成为研究热点之一。本文报道了一种新型的双功能荧光生物传感器，可用于对 Pb 和 Hg 进行无标记、特异性识别检测，具有高灵敏度和选择性。该传感器由富含鸟嘌呤的序列（AGRO100）和 N-甲基 mesoporphyrin IX（NMM）组装成 K 诱导的荧光 G-四链体探针。当与 Pb 和 Hg 离子结合时，探针分别转变为更稳定的无荧光 G-四链体结构和发夹样结构。因此，随着目标物的加入，荧光逐渐降低，可在 5 nM 和 18.6 nM 浓度下实现对 Pb 和 Hg 离子的分别检测。荧光强度与 Pb 和 Hg 浓度在 10-200 nM（R²=0.98）和 20-1000 nM（R²=0.99）范围内均呈线性相关。即使在含有 50 nM Pb 或 Hg 的实际湖水中，该双功能荧光探针也能对所有水样进行测定，回收率分别为 96%和 104%。考虑到该传感器无需标记、操作简单、节省时间、经济高效且易于处理，有望在各个应用领域推广应用于 Pb 和 Hg 的检测。
