Application Of The Fluorescent Probes In The Determination Of Sulfur-containing Amino Acids Metabolism And Sulfur Dioxide Detection

Studies have shown that sulfur dioxide and its derivatives can enhance the water-solubility of xenobiotics in the organism,which is conducive to the excretio of xenobiotics,but excessive sulfite can lead to internal biological lesions and produce a variety of diseases.In daily life,sulfur dioxide enters the living body mainly through two pathways.The first is the direct catalytic reaction of aspartate aminotransferases in the metabolism of sulfur-contaning aminon acids in the organsim to produce sulfur dioxide;the second is the release of sulfur dioxide from the atmosphere by the combustion of fossil fuels and the smelting of sulfur-contaning mineral,it is easy to form sulfite and bisulfite.The first case,we designed and synthesized an organic molecular probe to visualize the detection of cysteine metabolism in cells.For the second case,since the background in the air is complicated and there are many interferences,and the upconversion is excited by near-infrared light,there is no fluorescent impurity,so we use the upconversion probe to achieve the detection of sulfur dioxide.The specific research work is as follows:(1)8-bromooctanoic acid and 2,3,3-trimethylindolenine by nucleophilic substitution reaction to generate water-soluble intermediate product,and then through the Aldol condensation reaction with indole-6-carboxaldehyde synthesis of cyanine skeleton organic fluorescent molecules.By means of superconducting nuclear magnetic resonance spectroscopy,Waters Acquity UPLC-mass spectrometer,UV-Vis absorption spectroscopy,fluorescence spectroscopy and other characterization methods,a strong hydrophilic,high selectivity,high sensitivity organic fluorescence molecular probe.(2)Starting from the lanthanide metal acetate,Na YF4@Na YF4:Yb,Tm and Na YF4:Yb,Tm@Na YF4 were prepared by high temperature injections.Because of the uniform size,in the reaction system of high temperature oil phase,hydrophobic oleic acid molecules are wrapped on the surface of the upconverting nanoparticles.In order to improve the hydrophilicity of the upconverting nanoparticles,the oleic acid molecules on the surface are removed by glycolic acid stripping.In order to reduce the influence of the surface defects of the particles on the spectral performance of the upconverting nanoparticles,polyethyleneimine was modified on the surface of the ligand-free upconverting nanoparticles.By means of characterization with transmission electron microscopy,fluorescence spectroscopy and so on,we have obtained functionalized upconverting nanoparticles.(3)We use the functionalized upconversion nanoparticles as the donor of fluorescence resonance energy transfer and the synthesized organic fluorescence molecular probe with specific response to sulfur dioxide derivatives as the receptor of fluorescence resonance energy transfer through appropriate method to produce an upconversion probe,and the sulfur content of the sulfur dioxide derivative can be detected by changing the fluorescence of the upconversion nanoparticle by adding the sulfur dioxide derivative.