Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China; Environmental Monitoring Center of Fujian Province, Fuzhou, Fujian 350003, China.
Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, China.
Biosens Bioelectron. 2015 Oct 15;72:326-31. doi: 10.1016/j.bios.2015.04.039. Epub 2015 Apr 14.
In this paper, a novel label-free fluorescent biosensor for terbium (ш) (Tb(3+)) was proposed based on structural conversion of G-quadruplex DNA mediated by Thioflavin T (ThT) and Tb(3+). In the presence of K(+), ThT could bind to K(+)-stabilized parallel G-quadruplex, giving rise to high fluorescence intensity. Upon the addition of Tb(3+), Tb(3+) could competitively bind to parallel G-quadruplex leading to the structural change, which resulted in fluorescence decrease. The change of fluorescence intensity (ΔF=F0-F) showed a good linear response toward the concentration of Tb(3+) over the range from 1.0 pM to 10.0 µM with a limit of detection of 0.55 pM. This proposed biosensor was simple and cost-effective in design and in operation with ultrahigh sensitivity and selectivity. Thus, the proposed biosensor could be a promising candidate for monitoring ultratrace Tb(3+) in environment.
本文提出了一种基于噻唑蓝（ThT）和铽（Tb(3+)）介导的 G-四链体 DNA 结构转换的新型无标记荧光生物传感器来检测铽（ш）(Tb(3+))。在 K(+)存在的情况下，ThT 可以与 K(+)-稳定的平行 G-四链体结合，产生高荧光强度。当加入 Tb(3+)时，Tb(3+)可以与平行 G-四链体竞争结合，导致结构发生变化，从而导致荧光强度降低。荧光强度的变化（ΔF=F0-F）在 1.0 pM 至 10.0 µM 的 Tb(3+)浓度范围内呈现出良好的线性响应，检测限为 0.55 pM。该生物传感器在设计和操作上简单、经济，具有超高的灵敏度和选择性。因此，该生物传感器有望成为环境中超痕量 Tb(3+)监测的候选方法。
