Department of Chemistry, University of Cincinnati, OH, 45221, USA.
National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry & Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Anal Chim Acta. 2019 Sep 23;1072:75-80. doi: 10.1016/j.aca.2019.05.001. Epub 2019 May 4.
A highly specific and sensitive isothermal method for mercury detection using DNA-conjugated upconversion nanoparticles is reported. A single-stranded DNA containing thymine bases, used as the Hg-capturing element through the formation of thymine-Hg-thymine complex, is covalently attached to the NaYF: Yb Tm nanoparticles. Luminescence resonance energy transfer takes place between the NaYF: Yb Tm nanoparticles as donor and DNA-intercalating SYBR Green I as the acceptor upon excitation of 980 nm. The sensitivity and selectivity toward Hg are enhanced using the nicking enzyme, Nt. Alwl, which leads to signal amplification. By monitoring the ratio of acceptor emission to a reference peak, the presence of Hg ions are quantitatively determined with a lower detection limit of 0.14 nM, which is much lower than the US Environmental Protection Agency (EPA) limit of Hg in drinking water.
本文报道了一种利用 DNA 偶联上转换纳米粒子的高特异性和高灵敏度的等温汞检测方法。通过形成胸腺嘧啶-Hg-胸腺嘧啶复合物,将一条含有胸腺嘧啶碱基的单链 DNA 用作 Hg 捕获元件,共价连接到 NaYF:YbTm 纳米粒子上。在 980nm 激发下,NaYF:YbTm 纳米粒子作为供体与 DNA 嵌入型 SYBR Green I 之间发生荧光共振能量转移。使用切口酶 Nt.Alwl 增强了对 Hg 的灵敏度和选择性,从而实现了信号放大。通过监测受体发射与参考峰的比值,可以定量测定 Hg 离子的存在,检测限低至 0.14nM,远低于美国环保署(EPA)规定的饮用水中 Hg 的限值。