Synthesis And Study Of Fluoroboron Fluorescent Organic Small Molecular Probes

In recent years,the use of fluorescence imaging technology to monitor and analyze the content of biological micromolecules and physiological processes in cells and living organisms has received increasing attention from researchers.Efficient and sensitive biological imaging analysis can be realized by constructing an organic small molecule fluorescent probe with excellent performance.Due to its excellent properties such as high fluorescence quantum yield,strong light stability,and large rigid planar structure,a fluoroboroid(BODIPY)fluorescent dye has become a popular luminescent group.In this paper,4-pyridyl BODIPY was used as a fluorescent group,and different recognition groups were introduced on the nitrogen atom respectively.Two OFF-ON fluorescent probes BODIPY-DMTC and BODIPY-BB for detecting ClO~-were constructed.Based on the photoinduced electron transfer(PET)mechanism,the probe itself is in a fluorescence-off state,and when it interacts with ClO~-,the nitrogen atom is deprotonated,blocking the PET process and allowing the fluorescence to recover.In this paper,the response mechanism and photophysical properties of the two probes were systematically studied,and the change of fluorescence signal after probe and ClO~-response was explored.The specific work is as follows:(1)N,N-Dimethylthiocarbamoyl(DMTC)as the recognition group,firstly,the probe BODIPY-DMTC was designed and synthesized.Its structure was characterized by 1H NMR,13C NMR and HRMS;secondly,the photophysical properties of the probe in aqueous solution were investigated by fluorescence spectroscopy and UV-visible absorption spectroscopy.The experimental data show that BODIPY-DMTC has good light stability and exhibits high selectivity and high sensitivity to ClO~-.In the concentration range of 0-100 μM,there was a good linear relationship(R =0.995)and a low detection limit(95 nM);finally,the probe was successfully applied to the bioimaging analysis in cells(MCF-7 and RAW264.7)and in vivo(wild-type zebrafish).It showed good light permeability and responsiveness to ClO~-.Through cell co-localization experiments,the probes were targeted to mitochondria.(2)4-Hydroxyphenylboronic acid was selected as the recognition group.Firstly,the probe molecule BODIPY-BB was designed and synthesized.Its structure was characterized by 1H NMR,13C NMR and HRMS;Secondly,fluorescence spectrometry and U-V-visible absorption spectroscopy showed that BODIPY-BB has good light stability,selectivity and anti-interference,showing a good linear relationship(R2=0.9969)in the concentration range of 0-100 μM and low detection limit(0.6 μM);Finally,the probe was successfully applied to the cell(HepG2)for biological imaging analysis.It showed good response to ClO~-.Through the cell co-localization experiments,the probe was targeted to mitochondria.