Solvent-dependent Fluorescent Probes For Metal Ions

With the rapid development of the industrial and agricultural economy,human life and production activities have caused the environment to deteriorate.For example,mining,smelting,electroplating,printing,tanning and other industrial production activities have produced a large amount of wastewater containing heavy metal ions and polycyclic aromatic hydrocarbons.Landfills,municipal sewage,agricultural production,and urban residents'lives have also discharged a lot of heavy metal wastewater into the environment.Generally,methods for detection of metal ions are mainly including:atomic absorption spectrometer?AAS?,inductively coupled plasma mass spectrometer?ICP-MS?,inductively coupled plasma atomic emission spectrometer?ICP-AES?,atomic fluorescence spectrometer?AFS?,X X-ray fluorescence spectrum analyzer?XRF?,laser-induced breakdown spectrometer?LIBS?,etc.The above methods have quantitative and qualitative detection functions for heavy metals,but the instruments used are relatively expensive and the detection cost is high.Fluorescent probe technology is a newly developed method based on optical signal change.It has the advantages of highly detection sensitivity,good selectivity,low cost,and so on.This thesis was mainly completed as the following work:1.A new Schiff base fluorescent probe G1 was synthesized from 1-pyrene formaldehyde and isoniazid.Probe G1 was analyzed and characterized by infrared,single crystal,mass spectrometry,nuclear magnetic resonance,and scanning electron microscopy?SEM?.The fluorescent recognition abilility of probe G1 on was systematically evaluated by 22 common metal ions in different solvents.Experimental results suggest that the probe G1 appear selectivity for Co²⁺,Cu²⁺,Cr³⁺,Ru³⁺enhancent fluorescent has better selective fluorescence enhancement recognition effect on four kinds of heavy metal ions such as Co²⁺in 1-4-dioxane,Cu²⁺in DMF,CH₃OH and CH₃CN,Cr³⁺in CH₃CH₂OH,Ru³⁺in DMSO with enhanced fluorescent emission,respectively.UV-vis and fluorescence titration experiment and mass spectrometry data indicated that the coordination of metal iosn with G1 in a 1:1 molar ratio.2.Amphiphilic Schiff base fluorescent probe G2 was synthesized from triethylene glycol monomethyl ether and 1-pyrene formaldehyde.In aqueous solution,probe G2can self-assemble and aggregate to form a stable vesicle with yellow-green fluorescent emission.Experiment results show that probe G2 was highly selevtive for Fe³⁺with rationmetric fluorescent signal,and appears fluorescence quenching recognition of Pd²⁺in aqueous slotion,respectively.Further studies indicated that both of metal ions coordination with G2 in a molar ratio of 1:1.