Ural Federal University, 19 Mira Str., Yekaterinburg 620002, Russia.
Ural Federal University, 19 Mira Str., Yekaterinburg 620002, Russia; M. N. Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Science, 18 S. Kovalevskaya Str., Yekaterinburg 620108, Russia.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 May 5;292:122419. doi: 10.1016/j.saa.2023.122419. Epub 2023 Jan 26.
A series of fluorescent sensors based on small molecule were designed and fully characterised, demonstrating AIEE effect and revealing an outstanding ability to selectively detect Hg ions. The structural and electronic properties were studied through quantum chemical calculations at (Time-Dependent) Density Functional Theory ((TD)-DFT) level. Carboxamides of 2-Aryl-1,2,3-Triazoles (CATs) showed significant differences in their photophysical properties depending on the structure of the substituent at amino function on the C5-atom in the heterocycle. When the tert-cycloalkylamino group (pyrrolidine, piperidine, azepane) was attached, the triazoles exhibited highly intensive blue fluorescence, with quantum yields (QYs) up to 95 % and lifetime up to 6.9 ns in different solvents, whereas the QYs of congeners bearing secondary alkylaminogroups (viz., NHMe, NHCH-cyclo) indicate low QYs (1-10 %). Nevertheless, all types of the obtained fluorophores demonstrated excellent AIEE effect and formed fluorescent nanoparticles in a binary mixtures of organic solvents and water. The introduction of the carboxamide function enhances the sensing properties of 2-aryl-1,2,3-triazoles, providing a selective fluorescence quenching reaction in the presence of Hg. The fluorescence intensity of the CATs declines with the addition of 1.0 eq. of Hg into DMSO-water (v/v, 1:9). The other cations used did not induce any appreciable changes in fluorescence intensity. The CATs form a complex with Hg with highly specific detection for Hg over other competitive metal ions: the detection limits were determined to be 0.23 and 0.15 μM for the CATs 1b and 2c. The reverse effect was registered with the addition of ethylene diamine sodium salt; meanwhile, the CATs demonstrated more effective coordination with Hg in comparison with cysteine. This last finding, as well as the ability to detect Hg, is very valuable for application within biology and medicine.
设计并充分表征了一系列基于小分子的荧光传感器，这些传感器表现出聚集诱导发射（AIEE）效应，并具有出色的选择性检测 Hg 离子的能力。通过在（含时）密度泛函理论（(TD)-DFT）水平上进行量子化学计算，研究了它们的结构和电子性质。2-芳基-1,2,3-三唑的羧酸酰胺（CATs）的氨基功能上取代基的结构不同，其光物理性质也有显著差异。当连接叔环烷基氨基（吡咯烷、哌啶、氮杂环庚烷）时，三唑表现出高强度的蓝色荧光，在不同溶剂中的量子产率（QYs）高达 95%，寿命高达 6.9 ns，而具有仲烷基氨基取代基（即 NHMe、NHCH-环）的同系物的 QYs 则较低（1-10%）。然而，所有获得的荧光团都表现出优异的 AIEE 效应，并在有机溶剂和水的二元混合物中形成荧光纳米颗粒。引入酰胺官能团增强了 2-芳基-1,2,3-三唑的传感性能，在存在 Hg 的情况下提供了选择性的荧光猝灭反应。CATs 的荧光强度随着在 DMSO-水中（v/v，1:9）加入 1.0 eq.的 Hg 而降低。其他使用的阳离子没有引起荧光强度的任何明显变化。CATs 与 Hg 形成具有高度特异性检测 Hg 的配合物，超过其他竞争性金属离子：对于 CATs 1b 和 2c，检测限分别确定为 0.23 和 0.15 μM。加入乙二胺钠盐时会出现相反的效果；同时，CATs 与 Hg 的配位比半胱氨酸更有效。这最后一个发现，以及检测 Hg 的能力，在生物学和医学应用中非常有价值。
