Synthesis And Application Of Fluorescent Probes For Detection ·OH,HNO,HSO₃^- And ONOO^-

The redox balance in the organism is closely related to a variety of physiological processes and diseases.Reactive oxygen species(ROS),reactive nitrogen species(RNS)and reactive sulfur species(RSS)experience inter-reaction and interconversion to facilitate the dynamic balance of intracellular redox state.Their abnormal level can cause oxidative/reductive stress,which leads to cell apoptosis,aging and malignant transformation.Therefore,the development of a method to detect these active species is great significance for the analysis of the physiological and pathological mechanisms and the early diagnosis of diseases.This thesis focuses on the fluorescent probe technology that can convert chemical signals into optical signals,and targets important redox-active species in organisms including ·OH,HNO,HSO3-and ONOO-.The fluorescent probes for detecting four active species were synthesized through reasonable structure design.Then on the basis of its full characterization,the sensitivity,selectivity,anti-interference ability and recognition mechanism of the probe to identify the four active species were preliminarily studied.It is divided into the following four parts:The fluorescent probe of detecting reactive oxygen species ·OH:The probe Lyso-Nap-·OH was constructed using the naphthimide fluorophore and 3-methylpyrazolone,which recognizes the reaction site of ·OH.The probe recognizes·OH with some characteristics including high sensitivity,nanomolar detection limit,and wide pH application range.The fluorescent probe of detecting reactive nitrogen species HNO:The probe QM-HNO for detecting HNO was constructed using quinoline malononitrile unit with aggregation-induced luminescence(AIE)properties.QM-HNO spontaneously aggregates into nanoparticles in buffer solution to quickly and specifically respond to HNO.It has strong anti-interference ability and sensitivity.Finally,QM-HNO was used to successfully realize the visual imaging of exogenous HNO in HeLa cells.The fluorescent probe of detecting reactive sulfur species HSO3-:A near-infrared(NIR)probe TPA-BP-SO2 was constructed using the triphenylamine unit with AIE properties.The emission wavelength of the free probe reached 715 nm,and a new emission peak can be observed at 435 nm after encountering HSO3-.Therefore,the probe can be used as a dual excitation and dual emission probe to identify HSO3-.The fluorescent probe of detecting the reactive nitrogen species ONOO-and releasing the reactive sulfur species SO2:The new fluorescent molecule TFMU-SO2D was designed and synthesized as a dual function probe.TFMU-SO2D can release SO2 and the fluorophore with fluorescence off-on response via ONOO--triggered.TFMU-SO2D can be activated by nanomolar ONOO-in vitro and in HeLa cells to achieve a controlled release of SO2.