| Cell is the basic structural and functional unit of living organism.The cell function is closely related to the level of reactive oxygen species?ROS?.ROS are mainly derived from mitochondria,which include superoxide anion(O2·-),hydroxyl free radical?·OH?,hydrogen peroxide?H2O2?,singlet oxygen?1O2?,ozone?O3?,hypochlorous acid?HOC l?,hypobromous acid?HOBr?,lipid peroxide?ROOH?,etc.ROS maintain the cell homeostasis,participate in a wide range of physiological and pathological processes,and are closely related to signal transduction,cell differentiation,inflammation,cancer,senility,neurodegenerative injury,etc.Hypobromous acid is a kind of ROS,possessing similar physical and chemical properties to hypochlorous acid.The content of Br-in plasma is one-thousandth of Cl-.The endogenous hypobromous acid is generated by Br-and H2O2 under the catalysis of eosinophil peroxidase?EPO?.Therefore,the content of hypochlorous acid is much lower compared with that of hypochlorous acid,which makes the detection of hypobromous acid challenging.Besides,hypobromous acid has strong oxidizing property,playing an important role in immune defense and antibacterial application.The expression dysfunction of hypobromous acid will cause many diseases,including rheumatic arthritis,inflammatory tissue damage,cardiovascular diseases,neurodegenerative disease,nephrosis and cancer,etc.Compared with other biological detection methods,fluorescence microscopy has the advantages of high sensitivity,non-invasiveness,and high spatial resolution,providing an ideal tool for the investigation of active small molecules.Two-photon fluorescence imaging technology utilizes long wavelength light as the excitation source and has the advantages of deep tissue penetration,excellent light stability and reduced cell damage.Selenium?Se?is an essential trace element for human body and plays an important role in anti-oxidation,antagonizing harmful heavy metals and anti-cancer.It has been utilized to construct fluorescent probe for the detection of thiols and metal ions.In this paper,we synthesized two Se contained two-photon fluorescent probes for HO Br detection based on the cyclization reaction between Se and primary amine mediated by HOBr.And based on this,the fluorescent imaging of endogenous HO Br in living cel s was achieved.The studies were listed as following:?1?The hypobromous acid fluorescent probe?ABT-HO Br?was designed and prepared by introducing diphenyl selenide to benzothiazole via Suzuki coupling reaction.The Se=N bond was formed after ABT-HOBr reacted with HO Br,which inhibited the excited-state intramolecular proton transfer?ESIPT?process and resulted in the fluorescence quenching of the probe.ABT-HOBr responsed to HOBr with high sensitivity and selectivity and could be utilized to image the endogenous HO Br in living cel s.?2?Based on the mechanism of cyclization reaction between Se and primary amine mediated by HOBr,the fluorescent probe?NID-HOBr?was designed and prepared.In NID-HO Br,the naphthalimide was used as fluorescent dye and aminomorpholine was linked as the lysosome targeting group.N ID-HOBr responsed to HOBr with high sensitivity and selectivity and could be utilized to monitor the lysosome HOBr fluctuation in living cells.Meanwhile,the probe could be utilized to indirectly detect the activity of EPO. |
PDF Full Text Request