Study On The Synthesis And Performance Of Fluorescent Probe Based On Coumarin Imine

Coumarin has become a research hotspot because of its excellent fluorescence properties,simple synthesis,low toxicity and flexible structure.The introduction of various functional groups on the basis of it can form a unique structure.Because of its anti-cancer,anti-virus and anti-oxidation properties,it can be used in medicine,cosmetics and other industries.Due to its unique structure,it has formed some unique properties and can be used as a probe to identify ions.In addition,the imine bond（-C=N-）is usually a functional structure formed by the condensation of a carbonyl group and an amino group.It has excellent coordination ability with ions,so in this project,five probes were designed and synthesized based on coumarin to detect Al³⁺/Fe³⁺and arginine through fluorescence recognition or ultraviolet recognition.Fluorescent probes W1 and W2 based on the 3-aldehyde-4-hydroxycoumarin were synthesized.Among them,W1 can relay recognize Al³⁺/Fe³⁺in Et OH/H₂O medium.After adding Al³⁺to W1,the fluorescence changes from nothing to blue（under 365 nm ultraviolet lamp）,and then the fluorescence is quenched after adding Fe³⁺to the Al³⁺complex.And there will be a significant color change from colorless to bright yellow under visible light,which is different from other metal ions.So probe W1 can specifically and continuously recognize Al³⁺/Fe³⁺.W2 recognizes arginine through fluorescence/ultraviolet dual-channel in Et OH/H₂O（1:1）medium.The fluorescence increases after adding arginine to W2,and there is a significant change of color from colorless to yellow under visible light.And other amino acids do not significantly interfere with the recognition of arginine by W2,so probe W2 can be used in this system for colorimetric and fluorescence to turn on the dual-channel recognition of arginine.A fluorescent probe W3 based on the aminoacetophenone was synthesized,which can relay recognize Al³⁺/Fe³⁺in Et OH/H₂O medium.The fluorescence changes from nothing to blue after adding Al³⁺to W3,and then the fluorescence is quenched after adding Fe³⁺to the Al³⁺complex.And there will be a significant color change from colorless to light yellow under visible light,which is different from other metal ions.So probe W3 can specific and continuous recognition Al³⁺/Fe³⁺.Fluorescent probes W5 and W6 based on 3-amino-4-hydroxycoumarin were synthesized.Both can relay recognize Al³⁺/Fe³⁺in Et OH/H₂O medium.After Al³⁺is added,the fluorescence of W5 changes from nothing to cyan,and the fluorescence of W6 changes from nothing to blue,and the fluorescence are quenched after Fe³⁺is added to Al³⁺complex.And the color of W5-Al³⁺complex under visible light will change from yellow-green to brown-yellow after adding iron ions,which is different from other metal ions.Therefore,W5and W6 can specifically and continuously recognize Al³⁺/Fe³⁺.The probe is characterized by fluorescence spectroscopy,B-H curve and other methods,¹H NMR titration,mass spectrometry and other methods are used to estimate the binding ratio to infer the recognition mechanism,and linearly calculate its minimum detection limit to judge its sensitivity.