Preparation Of Coumarin-based Fluorescent Probes And Its Application In Biological Recognition

The mortality of tumor can effectively reduce by its early diagnosis,and the detection of relevant biomarkers can realize this goal.Fluorescent probe is a powerful detection tool and its simple operation,sensitive and fast reaction make it used widely in biological recognition and other fields.In this thesis,two fluorescent probes were designed by using coumarin as the fluorophore connected to the corresponding recognition group,which could be used for the fluorescence imaging of hydrogen peroxide and receptor tyrosine kinase respectively and provide new ideas for tumor diagnosis.Hydrogen peroxide is a kind of reactive oxygen species,which plays an important role in the proliferation and differentiation of tumor cells.CMB was prepared by reacting the aryl borate with hydroxycoumarin connected with morpholine group and its structure was determined by ~1H NMR and MS.Fluorescence spectra showed that it had a weak emission peak at 450 nm under the excitation of 400 nm.After adding H2O2,the fluorescence intensity at 450nm could achieve about 25-fold enhancement,which also exhibited good a linear relationship with the concentration of H2O2 in a range.CMB can respond to hydrogen peroxide selectively even under the interference of other competing species.This is because the aryl borate group reacts with H2O2 to change the structure of CMB,resulting in the enhanced fluorescence signal.CMB has good biocompatibility and can realize the imaging of exogenous and endogenous hydrogen peroxide in cells and zebrafish.Receptor tyrosine kinase is related to intracellular signal transduction and are overexpressed in certain tumor cells.SC1 was obtained by linking targeting group sunitinib malate with the coumarin fluorophore through long carbon chain,which could be used for the detection of receptor tyrosine kinases.When the probe was excited at 400 nm,it would produce two emission peaks at 460 nm and 590 nm.The intensity of the emission peak at 590 nm was basically unchanged,while the peak at 460 nm increased gradually with the increase of the enzyme concentration.SC1 can recognize receptor tyrosine kinases selectively in the interference of other related substances and can realize fluorescence imaging on the cell membrane of HT-29 cells overexpressing receptor tyrosine kinases.