Synthesis And Applications Of Fluorescent Probes For Detection Of Sulfur Dioxide Derivatives And Cellular Nucleus

Sulfite can be generated by sulfur dioxide(SO2),which is harmful for the environment.SO2 can be produced in situ in bodies and has unique physiological regulatory activity in cardiovascular system.However,excessive sulfite has toxic effects on humans and animals,leading to adverse reactions and diseases.The genetic material,DNA,is the main target of some anticancer drugs.Due to the low fluorescent quantum yield of natural DNA,it is necessary to search for exogenous fluorescent probes.This paper focuses on the design and synthesis of fluorescent probes for sulfite and DNA,and the main contents are listed as follows:In chapter 1,the sources and properties of SO2 and its derivatives were introduced,as well as the important role of DNA in organisms.Then,a summary of the previous relevant probes was summarized.In chapter 2,three fluorescent probes were designed and synthesized for the detection of sulfite by using benzocyanine as the chromophore based on intramolecular charge transfer(ICT).The design philosophy is as follows:the fluorescent probes selectively reacted with sulfites through nucleophilic addition reactions on the site of a,p-unsaturated double bond,leading to changing the photophysical properties of the probes.The identification properties for sulfites of three probes were compared firstly,and then the best one was selected for further investigation.Due to the low cytotoxicity and good cell permeability of the selected probe,we had successfully applied it in cell imaging experiments and achieved fluorescence detection of intracellular sulfites.In chapter 3,we designed and synthesized a green fluorescent probe for nuclear staining by using 6-aminoquinoline.Through UV,fluorescence spectrum and circular dichroism testing experiments,we found that both protamine DNA and calf thymus DNA could interact with the synthesized probe,leading the probe to accumulation in the nucleus.Because of the importance of cell nucleus in living organisms,the further biological applications for probes were tested.Compared with the commercial nuclear staining agent DAPI by the fluorescence confocal microscope cell imaging experiments,we found that the synthesized probe had good performance and could be used for the nuclear staining of living cells.