The Design,Synthesis And Application Of Fluorescent Probes For Detection Of Sulfur-compounding Compounds And Heavy Metals

Various bioactive molecules,such as sulfur compounds,metal ions and other,and the appropriate living environment for living molecules,such as pH,temperature,play key roles in maintaining the normal function of living body.As key messengers for signal transduction,sulfur-containing compounds play important roles in the physiological and pathological processes of living beings.Though metal ions are important sources for environmental pollution,they have important functions in human physiological processes,-including osmotic adjustment,catalysis,metabolism,and so on.Therefore,it is of pratieal need to develop analytical methods with high selectivities and high sensitivities to monitor sulfur compounds and heavy metals in the environment,food and living organisms.The main contents of this thesis are as follows:1.A novel fluorescent probe(E)-3-ethyl-2-(4-hydroxystyryl)-1,1-di-methyl-1H-benzo-[e]indolium iodide(probe EDB)based on benzo[e]indolium was synthesized,which could be used for the simultaneous detection of SO32-/HSO3-and HSO4-ion with different emission channels.Based on the principle of ion-induced rotation-displaced H-aggregates,when treated with NaHSO4,a fluorescence enhancement at 580 nm was observed with the excitation wavelength at 420 nm.While,in the advantage of the nucleophilic addition of SO32-to the vinyl group,strong fluorescence was obtained at 455 nm when treated with Na2SO3 with the excitation wavelength at 320 nm,along with obvious color change by naked eyes.The probe was also applicable for fluorescence imagings of bisulfite and hydrosulfate in HeLa cells.2.We designed and synthesized a new fluorescent probe HBN-TCF for the detection of SO2 derivatives.After the reaction between the probe with SO32-,a blue shift in fluorescence spectrum with a large emission distance(?? = 182 nm)was observed,which was excited at 400 nm The emission channel at 664 nm was decreased,along with the increasement of a new strong emission channel at 482 nm(?ex = 400 nm).And this probe exhibited rapid and selective detection of SO2 derivatives over other sulfur-containing species and featured a low-detection limit(82 nM).It could be used as a colorimetric and ratiometric fluorescent probe for detecting SO2 derivatives with high selectivity and high sensitivity.This new fluorescent probe was also successfully exploited for the fluorescence imaging of intracellular and exogenous SO2 and its derivatives in BEL-7402 cells.3.We have synthesized a novel long-wavelength fluorescent probe MFC for detection of palladium(Pd0).This probe not only shows high selectivity for palladium,but also could quickly discriminate different palladium species(Pd0,Pd2+,Pd4+)in phosphate buffered solution.After the reaction with Pd(PPh3)4,the UV absorption of the probe MFC shifts from 334 nm to 594 nm within a few minutes.The probe MFC conjugated with allky carbamate,which destroys the principle of intramolecular eharge transfer(ICT)and shows weak fluorescence.Based on the Pd0-catalyzed Tsuiji-Trost allylation reaction,the fluorogen was released and the fluorescence intensity at 612 nm was observed with 13-fold enhancement along with an obvious color change from yellow to purple with low detection limit.