College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Hunan University, Changsha, 410082, China.
College of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang, 453003, China.
J Fluoresc. 2017 Mar;27(2):643-649. doi: 10.1007/s10895-016-1993-y. Epub 2016 Dec 1.
This paper describes a label-free 17E DNAzyme-based time-gated fluorescence sensor for Pb detection by unmodified gold nanoparticles (GNPs) and a terbium ternary complex. The fluorophore that used in this paper is a terbium ternary complex. Its signal can be measured in a time-gated manner which could eliminate most of the unspecific fluorescent background. It is well known that unfolded single-stranded DNA (ssDNA) could be adsorbed on GNPs while double-stranded DNA could not. The cleavage of the substrate by the 17E DNAzyme in the presence of Pb causes the release of ssDNA from the 17E-17S duplex to be absorbed onto GNPs, preventing the aggregation of GNPs and then leading to a fluorescence decrease of terbium ternary complex. By means of this method, the authors have successfully detected Pb over a range of 10 nM to 2500 nM with a detection limit of 1.7 nM. The sensor also exhibited good selectivity. The sensor provided a simple, cost-effective, rapid and sensitive measurement tool for Pb detection.
本文描述了一种基于无标记 17E DNA 酶的时间门控荧光传感器，用于通过未修饰的金纳米粒子 (GNPs) 和铽三元配合物检测 Pb。本文中使用的荧光团是铽三元配合物。它的信号可以通过时间门控方式进行测量，这可以消除大部分非特异性荧光背景。众所周知，展开的单链 DNA（ssDNA）可以被 GNPs 吸附，而双链 DNA 则不能。在 Pb 的存在下，17E DNA 酶对底物的切割导致 ssDNA 从 17E-17S 双链中释放出来并被吸附到 GNPs 上，从而阻止了 GNPs 的聚集，然后导致铽三元配合物的荧光强度降低。通过这种方法，作者成功地在 10 nM 至 2500 nM 的范围内检测到了 Pb，检测限为 1.7 nM。该传感器还表现出良好的选择性。该传感器为 Pb 检测提供了一种简单、经济、快速和灵敏的测量工具。
