Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China.
Academy of Hi-Tech Research，Hunan Institute of Traffic Engineering, Changsha 421001, PR China.
J Hazard Mater. 2021 Sep 5;417:125975. doi: 10.1016/j.jhazmat.2021.125975. Epub 2021 May 8.
Mercury (Hg) is one of the most hazardous pollutants, widely distributed in water, atmosphere, and soil, while the Hg contents from different sources are greatly different. Until now, numerous reported methods are only suitable for a kind of sample because they cannot reconcile sensitivity and linear range. In this work, a tail-extensible DNA fluorescent probe for "turn on" detection of Hg with tunable dynamic range and high sensitivity was developed, which was based on segmental hybridization between silver nanoclusters (AgNCs)-covered DNA and different guanine-rich DNAs. By adding adenine-guanine-cytosine (AGC) base repeats as a tail of the guanine-rich DNA, the formation constant of T-Hg-T complex was effectively modulated within two orders of magnitude. Based on it, a tunable dynamic range from 0.035 to 0.2 pM to 8.0-120.0 pM was achieved by combining four fluorescent probes with different tail lengths. The Hgcontents from different sources were successfully measured. This evidenced the proposed sensor's application toward wide-field detection, which is useful for the direct and objective comparison of results from different sources, and therefore providing a way for solving the shortcomings of reported methods for Hg detection. Additionally,this present method is simple, cost-effective and time-saving, ultrasensitive and highly selective, which is favorable for expanding its applications and subsequent mercury pollution control.
汞（Hg）是最危险的污染物之一，广泛分布于水、大气和土壤中，而不同来源的 Hg 含量差异很大。到目前为止，许多已报道的方法仅适用于一种样品，因为它们不能兼顾灵敏度和线性范围。在这项工作中，开发了一种基于银纳米簇（AgNCs）覆盖的 DNA 和不同富含鸟嘌呤的 DNA 之间的分段杂交的“开启”检测 Hg 的可扩展 DNA 荧光探针，用于“开启”检测 Hg，具有可调动态范围和高灵敏度。通过在富含鸟嘌呤的 DNA 上添加腺嘌呤-鸟嘌呤-胞嘧啶（AGC）碱基重复作为尾巴，可以有效地调节 T-Hg-T 复合物的形成常数在两个数量级范围内。在此基础上，通过结合四种具有不同尾巴长度的荧光探针，实现了从 0.035 到 0.2 pM 到 8.0-120.0 pM 的可调动态范围。成功测量了来自不同来源的 Hg 含量。这证明了所提出的传感器在宽场检测方面的应用，这对于不同来源的结果的直接和客观比较很有用，因此为解决 Hg 检测的报道方法的缺点提供了一种途径。此外，本方法简单、经济高效、省时、超灵敏且选择性高，有利于扩大其应用范围和后续的汞污染控制。
