The Development Of Several Near-infrared Fluorescent Molecular Probes And Their Biological Imaging Analysis

Fluorescence imaging has become an indispensable tool in all areas of modern science and medicine.In recent years,the applications of small molecule fluorescent probes in biological sciences have grown significantly.Small molecule fluorescent probes are important multifunctional materials for studying biological systems.They can be easily loaded into cells and rapidly detect biological targets.In addition,the probe can be improved in terms of kinetics,excitation/emission wavelength and localization of specific organelles by optimizing the design strategies.Fluorescent probes with absorption and emission in the near-infrared?NIR?region?650-900 nm?have desirable properties,such as minimal photodamage to biological samples,deep tissue penetration and low interference with background autofluorescence.Three different near-infrared fluorescent molecular probes have been designed and synthesized to detect hydrazine,peroxynitrite and hydrogen sulfide respectively.The probe Cy-OAc capable of accurately and sensitively detecting hydrazine.The design strategy of probe Cy-OAc is that Benzo-phthalocyanine as the fluorophore and acetate group?Acetate?as the responsive group form a multifunctional fluorescent probe 2-(?E?-2??E?-2-acetoxy-3-??E?-2-?3-ethyl-1,1-dimetyhyl-1H-benzo[e]indol-2?3H?-ylidene?ethylidence?cyclohex-1-en-1-yl?vinyl-3-ethyl-1,1-dimethyl-1H-benzo[e]indol-3-ium.After adding the object to be tested,the acetate portion of the probe Cy-OAc will be selectively hydrazinolysis and the fluorescence signal is changed.The probe exhibits excellent selectivity,accuracy and the low biotoxicity.The concentration of hydrazine in living cells and vivo can be detected under physiological conditions.These characteristics enable the probe to be a good tool for the accurate detection of hydrazine in living systems.A near-infrared cyanine dye heptamethyl cyanine is used as a fluorophore,and p-aminophenol as a responsive group synthesize a fluorescent probeCy-OH 1-ethyl-2-??E?-2-??E?-3-??E?-2-?1-ethyl-3,3-dImethylindolin-2-ylidene?ethylidene?-2-??4-hydroxyphenyl??methyl?mino?Cyclo hex-1-en-1-yl?vinyl?-3,3-dimethyl-3H-indol-1-ium,which achieve a ratiometric fluorescence response.In addition,the probe Cy-OH can be used to visualize both exogenous and endogenous peroxynitrites in RAW264.7 macrophages.The design strategy of probe DCMB-NO₂?E?-2-?2-?2-?6-?2,4-dinitrop henoxy?naphthalen-2-yl?vinyl?-4H-chromen-4-ylidene?malononitrile isadding 1,4-dinitrofluorobenzene into a dinitrile methylene-benzopyran derivative as a reaction site for rapid detection of H₂S in aqueous solution.It is highly selective for H₂S compared to the analytes containing common ions and other sulfides,in addition,it has been shown to detect H₂S in living cells.