Construction Of Novel Fluorescent Probes For F^-,ClO^- And HSO₃^- And Their Analytical Application

Both exogenous and endogenous anions play crucial roles in various life processes,and an imbalance in the concentration of specific anions within cells can have very serious effects on the body.Silver ion(Ag+),fluoride ion(F-),hypochlorite ion(ClO-)and bisulfite(HSO3-)play irreplaceable roles in the biological immune system and the aging process of organisms.Excess or lack of these ions in cells can lead to serious disease,such as neurological disease,liver degeneration,cardiovascular disease and even cancer.Therefore,the development of sensitive,highly selective,and facile methods for monitoring the changes of F-,ClO-and HSO3-in the environment,in vivo,and even in clinical diagnosis is of great significance.In this paper,novel triphenylmethane derivatives and ESIPT fluorescent dyes were designed and prepared,and the properties of the dyes were systematically studied.A new method for the detection of hypochlorite ion,sulfite ion and fluoride ion was developed based on the above dyes.The results showed that the methods have the advantages of high sensitivity,good selectivity and good biocompatibility.The specific work performed in this paper is as follows:(1)A solvent-mediated ESIPT reactive fluorescent dye was synthesized,and the detection of F-and Ag+was realized by the sensitive and selective response of the dye to Fand Ag+.In addition,the probes performed high-resolution imaging of living cell cilia.ESIPT fluorophores exhibit strong interconversion fluorescence in protic solvents and normal emission in aprotic solvents,which is very different from traditional ESIPT molecular compounds.The interaction of F-with hydrogen bonds and the chelation of Ag+with the ESIPT moiety of 2-PPN both lead to the changes in its tautomers and thus changes in fluorescence intensity.On this basis,a detection method for F-and Ag+ based on 2-PPN was established.The detection limits for F-and Ag+were 2.4 nM and 1.5 nM,respectively.The results of selectivity experiments showed that in the same medium and in the presence of other inorganic ions,the fluorescence of 2-PPN does not change,and it exhibits high selectivity to F-and Ag+.MTT experiments proved that the probe 2-PPN has low cytotoxicity and good cell membrane permeability.The probe was further successfully applied to in vitro cilia imaging of MCF7 cells,showing its high-resolution imaging performance.(2)A triphenylmethane fluorescent dye(WY)was designed and synthesized,the sensitivity of this dye to bisulfite ions was evaluated and a method for WY detection of bisulfite ions was established.First,fluorescent dyes were prepared from 3-methylindole,dimethyldichlorosilane and p-dimethylaminobenzaldehyde.The structure was analyzed by Mass Spectrometry(MS),Nuclear Magnetic Resonance Spectroscopy(NMR),Infrared Spectroscopy(IR),ultraviolet-visible absorption spectrometry(UV-vis),X-ray fluorescent emission spectrometer,the fluorescent probe WY can identify bisulfite ion well.In the presence of bisulfite in the dye solution,WY interacts with HSO3-,that is,bisulfite attacks the C=C structure of WY and undergoes an addition reaction,thus resulting in the change of the chemical structure of WY.The color of the solution changed from light green to dark green,and the fluorescent color changed from light yellow to blue under UV light.Based on this principle,WY quantitatively detects HSO3-with a detection range of 5～45 μM and the detection limit of 7.50×10-4 mM.(3)A fluorescent dye(BQ)was synthesized with 5-bromo-indole-3-methane.The sensitivity of the dye to bisulfite ions was studied,and a method for BQ detection of bisulfite ions was established.The structure was analyzed by Mass Spectrometry(MS),Nuclear Magnetic Resonance Spectroscopy(NMR),Infrared Spectroscopy(IR),ultraviolet-visible absorption spectrometry(UV-vis),X-ray fluorescent emission spectrometer,the fluorescent probe BQ can identify bisulfite ion well.When bisulfite exists in the BQ dye solution system,BQ interacts with HSO3-,that is,bisulfite attacks the C=C structure of BQ,and an addition reaction occurs,thus changing its own conjugated structure.The color of the solution changes from red to blue,and the fluorescent color changes from red to blue under UV light.Based on this principle,a quantitative detection method for HSO3-was established.The detection range was 5～40 μM and the detection limit was 7.36×10-5 mM.(4)3-methylindole,4-hydroxybenzaldehyde and dimethyldichlorosilane were used as raw materials to synthesize the fluorescent probe DPC,which has good selectivity and high sensitivity.The sensitivity of the dye to hypochlorite ion was tested,and a method for DPC detection of ClO-was established.The structure was analyzed by Mass Spectrometry(MS),Nuclear Magnetic Resonance Spectroscopy(NMR),Infrared Spectroscopy(IR),ultraviolet-visible absorption spectrometry(UV-vis),X-ray fluorescent emission spectrometer,the fluorescent probe DPC can identify ClO-well.When ClO-exists in the DPC solution system,hypochlorous acid cuts off the C=O double bond of triphenylmethane derivatives and oxidizes to generate aldehyde groups.The fluorescence of the solution changed from blue to yellow under UV light.Based on this mechanism,DPC was used to quantitatively detect ClOwith a detection range of 5～40 μM and a lower detection limit of 3.51 × 10-4 mM.