Synthesis And Properties Of Near-Infrared Fluorescent Probes Based On Benzopyrylium

Fluorescent probes have attracted widespread attention in the field of optical imaging and analytical sensing because of their high sensitivity and fast response.As a derivative of sulfur dioxide,HSO3-is the main component of active sulfur substances,which is important antioxidant and antioxidant metabolites.H2S is a gas transfer agent that plays an important role in intracellular processes in mammals,and is also a neuroprotective and neuromodulator in the brain.Viscosity plays a vital role in the biological microenvironment.Therefore,it is of great significance to synthesize fluorescent probes for detecting HSO3-,H2S and viscosity.The main contents are as follows:1.Using 3-aminophenol as raw material,the target compound BAOA was synthesized through a four-step reaction.Based on the research of ultraviolet-visible and fluorescence sensing properties,the probe BAOA can be used for ratiometric fluorescence detection of HSO3-,and the detection limit is 63.1 nmol/L.The probe BAOA has good selectivity,strong anti-interference ability and fast response.Nuclear magnetic titration and mass spectrometry analysis showed that the recognition mechanism was the Michael addition initiated by HSO3-.In addition,BAOA has the ability of mitochondrial and lysosomal co-localization,which can also be used in the detection of HSO3-in cells.2.A ratiometric fluorescent probe HABA was synthesized using 3-aminophenol as the starting material.The detection properties of the probe HABA toward H2S were tested by ultraviolet-visible absorption spectroscopy and fluorescence emission spectroscopy.A good linear relationship was obtained between the fluorescence intensity ratio at 503 nm and 685 nm(I503/I685)with the concentration of H2S in the range of 0-100 ?mol/L,and the detection limit was calculated to be 1.11 ?mol/L.Besides of its good selectivity and strong anti-interference ability,probe HABA can also detect H2S in the pH range of 6-10.Cell experiments indicated that HABA had mitochondrial and lysosomal localization ability,and the probe could be used in the detection of endogenous and exogenous H2S in cells.3.Two near-infrared fluorescent probes DMPC and DEPC were synthesized,which can be used to detect viscosity.The study of their photophysical properties showed that the fluorescence quantum yield of the two probes in low-viscosity solvents(DMSO,CH3CN,EtOH,DCM,CHCl3)were lower,while that in high-viscosity solvent glycerol was significantly enhanced.Under the excitation of 700 nm light,it was found that there was a good linear relationship between the logarithmic of the solution viscosity(log ?)and the logarithmic of the fluorescence intensity at 745 nm(log I745),and the probes can be used in the detection of the viscosity change via fluorescence method.