Synthesis And Fluorescence Imaging Properties Of The Bioactive Species Sensor-Molecules

Bioactive species such as reactive oxygen species,reactive sulfur species reactive carbonyl species and enzymes play crucial roles for participating the metabolism of intracellular materials,regulating the corresponding biological functions,and maintaining the homeostasis and normal physiological functions of the living cells because of their high reactivity and catalytic activity.Therefore,the detection and monitoring of the bioactive species is of great biological and medical significance for researching their biological functions and effects,and revealing the physiological function and pathology related to the human health and diseases.In recent years,thanks to the development of the fluorescence imaging techniques,the fluorescent probes techniques have been emerged as a powerful means to detect and track bioactive species in living systems.Herein,to solve some key problems of the reported biactive species sensor-molecules,the highly selective and organelles-targeted sensor-molecules based on the original deep-red and near-infrared fluorescent dyes and the new detection models have been developed.The main contents from following aspects:The deep-red emitting acenaphthene/naphthalimide-xanthene dye,R1 and R2,have been synthesized based on the intramolecular S_NAr^H reaction.The dye R2 exhibits high fluorescence quantum efficiency,good photostability and remarkable lysosome-targeted ability.By labeling and tracking the changes of the concentration and viscosity of the autophagolysosomes,the dye R2 has been applied for the fluorescence imaging of the starvation-and rapamycin-induced autophagy in living cells.The near-infrared emitting selenoxanthene-cyanine dye Se Cy has been synthesized by substituting the O atom in xanthene with Se atom.Then,the mitochondrial-targeted sensor-molecule Se Cy-H derivated from the original dye Se Cy by the introduction of the aryl boric acid group as the recognition group for H₂O₂.The sensor-molecule Se Cy-H shows high selectivity for the detection of H₂O₂ with a low detection limit(2.43?M),and can be used for imaging endogenous H₂O₂ induced by PMA in living cells and derived from O₂·^-in autophagy.Therefore,the sensor-molecule Se Cy-H can be used for the research of the autophagy.The deep-red emitting thioxanthene-indole dye SHCy,and the near-infrared emitting thioxanthene-benzoindole dye SBHCy have been synthesized by substituting the O atom in xanthene with S atom,and applied for developing the organelle-targeted sensor-molecules for the highly detective detection of the bioactive sulfur species.The sensor-molecules SHCy-C and SBHCy-C based on the original dye SHCy and SBHCy are synthesized by the introduction of the acrylic group as the reaction site.They show high selectivity and sensitivity for detecting Cys(the detection limit is 16 n M and 83n M).Meanwhile,the sensor-molecules SHCy-C and SBHCy-C can image endogenous Cys in lysosomes and mitochondrions.Meanwhile,by the trifluoromethanesulfonylation of the hydroxyl group in SBHCy,a mitochondrial-targeted sensor-molecule SBHCy-H is developed for the high selective and sensitive detection of H₂S(the detection limit is 28.5 n M)based on the nucleophilic addition of H₂S and the charged electron-deficient C=N double bond within the benzo[e]indolium moiety.Moreover,the sensor-molecule SBHCy-H can image the endogenous H₂S biosynthesized from Cys and GSH and generated in antioxidant stress.By increasing the reaction steric hindrance,the naphthalimide-based sensor molecules Np modified by ortho-phenylenediamine derivative groups have been obtained.Compared with the n-propyl group,the isopropyl-modified ortho-phenylenediamine group reacts specifically with formaldehyde(FA)to form a naphthimide-imidazole derivative with high fluorescence quantum efficiency,which result in the sensor-molecule Np-a2 shows high selectivity for detecting FA.Meanwhile,Np-a2 realizes the turn-on detection of FA and the fluorescence imaging of endogenous FA in living L929 cells.Besides,by the introduction of the hydroxyl group and the morpholine group respectively,the water-soluble sensor-molecule Np-b and the lysosomes-targeted sensor-molecule Np-c have been synthesized for the specific detection and imaging of FA in living cells.The sensor-molecule SHCy-P via the phosphorylation of the hydroxyl group in SHCy is synthesized based on because the acid phosphatase catalyzes the hydrolysis of orthophosphate monoesters.Spectroscopic studies show that SHCy-P can detect acid phosphatase with high selectivity and sensitivity(the detection limit as low as 0.48 U/L)in a wide p H range.More importantly,SHCy-P with remarkable lysosomes-targeted ability has been applied for imaging the acid phosphatase in living PC-3 and HeLa cells.