Design,Synthesis And Properties Of Recognition Hg²⁺ And F^- Fluorescent Probe

Fluorescence probes are important as detection methods in environmental chemistry,analysis chemistry and life sciences.In terms of detection of a particular substrate,fluorescent probes relative to conventional detection methods showed the advantages of rapid identification,high sensitivity,simple operation and good choices,and have broad application prospects in the field of detection.The fluorescent probe of Hg²⁺or F^-ion is designed and synthesized for Hg²⁺ions and F^-ions currently have important detection significance.The spectrum properties and mechanism of action were studied.The main research contents are:1.A fluorescent probe molecule with coumarin and phenoxazine structural units was synthesized for the selective recognition of Hg²⁺ions.By modifying the thioacetal group at position 3 of the coumarin and phenoxazine,a fluorescent probe was designed based on the deprotection of the thioacetal group promoted by Hg²⁺ions.The acetal aldehyde interacts with Hg²⁺ions to generate the corresponding aldehydes.Due to the expansion of the molecular conjugated system after the action of Hg²⁺ions,the fluorescence of the probe is increased dozens of times.The detection limits of several fluorescent probes is about 10^-8mol/L.This probe has the characteristics of strong anti-interference ability,fast response speed,high sensitivity,and good selectivity to Hg²⁺ions in a wide pH range.2.Fluorescence probe molecules with coumarin structural units,due to the introduction of the electron group,resulting in a probe having a certain fluorescence,and fluorescence there between when detecting Hg²⁺ions may cause interference to detect the fluorescent signals.In order to solve this problem,the carbonyl group in the coumarin structure is replaced with a thiocarbonyl group.With the introduction of the sulfur atom,the fluorescence of the coumarin structure itself is significantly reduced,and the color of the solution is significantly deepened.The solution fading and fluorescence emission from an incorporated significant change are significantly changed when responding to the Hg²⁺ion.Whether it is a naked eye observation or a fluorescent signal detection,it can reflect the presence of Hg²⁺ions.This detection limit of this probe is 7.84×10^-9 mol/L,which has a large decrease in fluorescent probes before the modification.3.A series of fluorescent probes molecules having imidazole modified coumarins were synthesized for detecting F^-ions.This series of probes is designed based on the characteristics of small radius,strong electrical negativeness,high charge density.The fluoride ion binding of the fluoride ion binds to the imidazole,resulting in a molecular hydrogen bond that originally maintained molecular plane,thereby exhibiting the characteristics of fluorescence emission decline.Through the study of the spectral properties of the series,it is found that the electronization group is more conducive to the stability of the probe molecule after the proton,and the F^-ion sensitivity is the highest.The detection limit was determined to be 3.50μmol/L.