Synthesis And Application Of Long-wavelength Emission Fluorescent Probe Based On TCF Derivatives

Tricyanofuran（TCF）as a strong electron-absorbing acceptor,has been widely used to construct long-wavelength emission fluorescent probes by taking advantage of the effective ICT（intramolecular charge transfer）effect in the intramolecular conjugation system.Because of its simple synthesis method and easy availability of raw materials,several probes with TCF derivatives as fluorophores were synthesized in this paper,and the recognition and spectral properties of the probes for different substances to be measured were investigated,the results are as follows:1.The fluorescent probe TCF-EA was synthesized by condensation of4-（2-hydroxyethyl）amino)benzaldehyde with TCF,which showed specific recognition of oxalyl chloride in dry dichloromethane solution,the limit of detection exhibited 2.902×10^-6M and a rapid response to oxalyl chloride（<5 min）.The probe has a dual channel response to oxalic acid chloride with fluorescence spectra and UV-Vis absorption spectra,and the color of the test solution changes from pink to light yellow,and complete burst of fluorescence occurs.The mechanism study showed that the probe TCF-EA underwent amidation and esterification tandem reaction with oxalic acid chloride.In addition,the probe can be used to prepare test strips for the rapid and convenient detection of oxalyl chloride in the gas phase.2.The fluorescent probe TCF-DN,a TCF derivative with thiocarbonate as the recognition group,was synthesized using 6-hydroxy-2-naphthala-ldehyde as the substrate.The probe was sensitived to Hg²⁺,while the probe had long wavelength emission and large Stokes shift（160 nm）.Cell imaging studies showed that the probe TCF-DN has low toxicity to cells and can be used to detect Hg²⁺in living cells.3.The fluorescent probe TCF-OH was synthesized using4-（（2-（2-hydroxyethoxy）ethyl）amino）benzaldehyde as a substrate,and the probe was effective in detecting HSO₃^-in DMSO/H₂O（2/8,v/v,Tris 10 m M,p H=7.4）solution with a detection limit of 2.3×10^-7M,the probe TCF-OH underwent a nucleophilic addition reaction with bisulfite,which blocked the molecular conjugation system and led to fluorescence burst.In addition,TCF-OH can be successfully used to detect HSO₃^-in water samples and living cells.