| Mercury compounds are highly toxic and have a great harm to human health and the environment,and are one of the serious heavy metal elements.Elemental mercury can be enriched along the food chain.Since humans cannot directly metabolize mercury,mercury will accumulate in the human body,which may eventually lead to many diseases that are difficult to cure.For example,after the metal mercury in the blood enters the brain tissue,it is oxidized into mercury ions and accumulates in the brain tissue,thereby causing irreversible damage to the central nervous system.In addition,after the mercury ions are transferred to the kidneys,they will also affect the kidneys and cause symptoms such as nephrotic syndrome.Therefore,it is very important to quickly identify mercury ions in the environment and organisms.This thesis adopts an efficient and convenient chemical method-fluorescent probe method to achieve an accurate response to mercury ions.In thesis paper,an N-phenyl 15-crown ether(NTO)with oxysulfur heteroatom was applied as the mercury ion recognition group,and a new class of near-infrared mercury ions fluorescence probes were designed.The main contents are as follows:1.The harm of mercury ions and common detection methods are briefly described,and the advantages of fluorescence probe method are summarized.The research status of mercury ion probes is summarized according to the different fluorescence signals generated after combining with mercury ions,then the research content of this paper is proposed.2.Using N,N-dihydroxyethylaniline,phosphorus tribromide,2,2'-(1,2-ethanediyldioxo)diethyl mercaptan as raw materials,a kind of Sulfur heteroatom N-phenyl 15 crown ether(NTO)as a mercury ion recognition group,the author connected them to(3,5,5-trimethylcyclo hex-2-enylidene)malono nitrile fluorophore to prepared a new mercury ion fluorescent probe-MNC.The structure was characterized by NMR,ESI-MS,etc.,and its mercury ion response was tested by ultraviolet analyzer and fluorescence spectrometer.The results showed that the UV absorption and fluorescence emission of the probe MNC were located at 520 nm and 672 nm,respectively.After adding Hg2+,the solution color changeed from red to yellow.In addition,the spectrum changed significantly,and the maximum absorption wavelength shifted blue from 520 nm to 400 nm.In the fluorescence spectrum,the fluorescence emission peak at 672 nm was significantly weakened.After calculation,the binding constant of MNC and Hg2+ is 1.6×105 M-1,and the detection limit is 8.33×10-5 mol/L.What's more,MNC has been successfully used to detect Hg2+ in biological samples,cells and zebrafish.3.On the basis of the second part,NTO was connected with fluoroboron dipyrrole(BODIPY)fluorophore,and an near-infrared mercury ions probe(NTO-BDP)was prepared by extending its ultraviolet absorption wavelength and fluorescence emission wavelength to the near-infrared region by extending its conjugated structure.The structure was characterized by NMR and ESI-MS,and the mercury response was measured by UV analyzer and fluorescence spectrometer.The results showed that the UV absorption and fluorescence emission of the probe NTO-BDP were located at 750 nm and 809 nm,respectively.After adding Hg2+,the solution color changeed from dark green to cyan.In addition,the spectrum changed significantly,and the maximum absorption wavelength shifted blue from 750 nm to 670 nm.In the fluorescence spectrum,the fluorescence emission peak at 809 nm was significantly enhanced.After calculation,the binding constant of NTO-BDP and Hg2+ is 6.4×104 M-1,and the detection limit is 2.66×10-4 mol/L.Also,NTO-BDP can used to detect Hg2+in biological samples,cells and zebrafish. |
PDF Full Text Request