College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Sensors (Basel). 2018 Nov 16;18(11):3998. doi: 10.3390/s18113998.
The interaction between polythymine (dTn) and 5,10,15,20-tetrakis(N-methyl-4-pyridyl) porphyrin (TMPyP) was systematically studied using various techniques. dTn remarkably enhanced the fluorescence intensity of TMPyP as compared to other oligonucleotides. The enhanced fluorescence intensity and the shift of the emission peaks were ascribed to the formation of a - complex between TMPyP and dTn. And the quenching of the dTn-enhanced fluorescence by Hg through a synergistic effect occurs due to the heavy atom effect. The binding of Hg to TMPyP plays an important role in the Hg-TMPyP-dT ternary complex formation. A TMPyP-dT-based Hg sensor was developed with a dynamic range of Hg from 5 nM to 100 nM. The detection limit of 1.3 nM was low enough for Hg determination. The sensor also exhibited good selectivity against other metal ions. Experiments for tap water and river water demonstrated that the detection method was applicable for Hg determination in real samples. The Hg sensor based on oligonucleotide dT-enhanced TMPyP fluorescence was fast and low-cost, presenting a promising platform for practical Hg determination.
采用多种技术系统地研究了多聚胸腺嘧啶核苷酸（dTn）与 5,10,15,20-四（N-甲基-4-吡啶基）卟啉（TMPyP）之间的相互作用。与其他寡核苷酸相比，dTn 显著增强了 TMPyP 的荧光强度。增强的荧光强度和发射峰的位移归因于 TMPyP 和 dTn 之间形成的 - 配合物。由于重原子效应，Hg 通过协同效应使 dTn 增强的荧光猝灭。Hg 与 TMPyP 的结合在 Hg-TMPyP-dT 三元配合物的形成中起着重要作用。基于 TMPyP-dT 的 Hg 传感器具有从 5 nM 到 100 nM 的 Hg 的动态范围。检测限低至 1.3 nM，足以用于 Hg 测定。该传感器对其他金属离子也表现出良好的选择性。自来水中和河水中的实验表明，该检测方法适用于实际样品中的 Hg 测定。基于寡核苷酸 dT 增强 TMPyP 荧光的 Hg 传感器快速且成本低，为实际 Hg 测定提供了有前途的平台。
