College of Chemical and Materials Engineering, Anhui Science and Technology University, Fengyang 233100, China.
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116000, China.
J Phys Chem A. 2022 Jan 20;126(2):230-238. doi: 10.1021/acs.jpca.1c08151. Epub 2022 Jan 7.
Fluorescence sensors based on small organic molecules are drawing increasing attention. In this contribution, the underlying detection mechanism of a typical fluorescence sensor for 2,4,6-trinitrophenol (TNP) based on fluorescence quenching is comprehensively investigated. The TNP molecule is proved to plant an intermolecular electron transfer state (dark state) below the bright state. Strong π-π interaction is observed between the sensor and TNP, which provides considerable orbital overlaps between the sensor and analyte. Electron transfer from the sensor to analyte is facilitated by such a strong interaction, which quenches the sensor's fluorescence. The design strategy for such TNP sensors is proposed based on the detection mechanism, and a series of new sensors is designed, which is likely to have better sensitivity than the original sensor.
基于小分子的荧光传感器越来越受到关注。在本贡献中，全面研究了基于荧光猝灭的典型 2,4,6-三硝基苯酚（TNP）荧光传感器的基本检测机制。证明 TNP 分子在亮态之下存在分子间电子转移态（暗态）。在传感器和 TNP 之间观察到强烈的π-π相互作用，这为传感器和分析物之间提供了相当大的轨道重叠。这种强相互作用促进了从传感器到分析物的电子转移，从而猝灭了传感器的荧光。基于检测机制提出了这种 TNP 传感器的设计策略，并设计了一系列新的传感器，它们可能比原始传感器具有更好的灵敏度。
