Synthesis And Application Of Ratiometric Fluorescent Probes Based On The Benzimidazole,Hemicyanine And Coumarin

In our physical system,there are a large amount of ions,including anions,cations and bioactive small molecules,they play important roles in the process of life,such as SO32-,OCl-Cu2+,Zn2+ and Cys.In vivo,these ions and small molecules maintain a dynamic balance.When the balance system was broken,the body of metabolism was disordered followed by a variety of discomfort and diseases,therefore,it is urge to research and detect the application value of ions and small molecules in these organisms.So far,there are many methods for the detection of these ions and small molecules,the fluorescence probes attract more and more researcher's interest because of their easy operation,high sensitivity,low cost and less harm to biological cells.In this paper,several fluorescent probes were designed and synthesized based on fluorophores such as coumarin,hemicyanine,benzimidazole and pyridine.The analyte in cells were also detected,such as hypochlorous acid and sulfite,including the next contents:1.Aratiometric fluorescence probe for sulfite based on the ICT mechanismBased on the high fluorescence quantum yield and electron-donating ability of benzimidazole and the strong nucleophilicity of sulfite,we designed and synthesized a ratiometric fluorescent probe(ZSO)for sulfite based on the mechanism of aldehyde addition,For the probe ZSO,the N atom has stronger electron-donating ability in benzimidazole,and the aldehyde group has strong electron-getting ability,so they formed a strong push-pull system,ICT was carried out smoothly and showed the green fluorescence.When the aldehyde reactd with sulfite,the electron-getting ability of the aldehyde was greatly weakened,resulting in blocking the ICT and wavelength occurred blue shift and displayed blue fluorescence.The probe had the strong selectivity,anti-interference,rapid response time(within 30s)and was successfully applied in the HeLa?HepG2?L-02 cells with the brilliant performance and few toxicity.2.A novel fluorescent probe based on the benzimidazole-hemicyanine for the HOC1Based on the previous detecting results of the fluorescent probe constituted of benzimidazole,we synthesized the ratiometric fluorescent probe(ZBM-H)combined with the benzimidazole-hemicyanine,it has large fluorescence emission wavelength(659 nm),better selectivity toward hypochlorite.It can also detect brilliantly endogenous and exogenous hypochlorous acid in RAW264.7 cells under lower toxicity,it has brilliant colocalization coefficient of ZBM-H and Lyso-Tracker Deep Red.3.A mitochondria-targeted ratiometric fluorescent probe for sulfite base on the FRET/ICT mechanismCoumarin has a strong light stability,larger stokes shift and fluorescence quantum yield.The hemicyanine has a long emission wavelength,greater selectivity for sulfite.There are larger overlap between the emission of coumarin and the excition of hemicyanine.Thus,we designed and synthesized a fluorescent probe(Zcn-hy)for sulfite,which is based on the FRET/ICT mechanism and constituted of coumarin-hemicyanine.After added sulfite,the FRET/ICT mechanism was stopped.In a series of test results of Zcn-by in the approximate physiological environment,it has higher selectivity,lower detection limit,it was also applied successfully to the HeLa,L-02 and HepG2 cells with less toxicity,litter harmful for the normal cells.4.A water-soluble ratiometric fluorescent probe for the hypochlorousIn this paper,considering the larger overlap with the fluorescence emission of the coumarin and the absorption of the pyridinium,and the pyridinium has better watersoluble,we synthesized a ratiometric fluorescent probe for hypochlorous acid based on the coumarin-pyridinium.The probe has better mitochondria-targeted coefficients,better water solubility.It can complete in the 5%of EtOH.After added hypochlorous acid,the fluorescence changed from orange to blue and the FRET was off.