Study On The Detection And Imaging Of Metal Ions Based Novel Aggregation-induced Fluorescent Molecules

The Schiff base compound has good spectral properties and coordination ability,due to containing C=N in its structure.It has important research significance in the detection of metal ions,because there are many merits for Schiff base compound,like as simple synthetic route,high yield,rich in raw materials and a wide of choice,and coordinated many metal ions with N,O,S and other heteroatoms of the molecular structure.Fluorescent probes have the advantages of simple operation,high selectivity and sensitivity,good time and space identification.Aggregation-induced emission fluorescence probe is an important branch in the research areas of fluorescent probes.It has great potential for chemical and biological sensing,medical imaging,and has been successfully applied to metal ions,organic small molecules,pathogens,Protein,DNA and other biological molecules.However,it is still a challenge to develop simple small molecular probes with great optical property and recognition ability.Therefore,a series of novel fluorescent probes with aggregation-induced emission characterization were designed for the detection of metal ions in the paper,which perform high luminious efficiency.We successfully realize sensing or imaging for target substances with high sensitivity and selectivity.The main research contents are as follows:?1?A simple Schiff base compound as probe was synthesized for the detection of Al³⁺,based on salicylaldehyde and biphenyl diamine.The probe has the characteristic of aggregation-induced emission?AIE?enhancement.The probe can detect Al³⁺,due to coordinating Al³⁺selectively with the hydroxyl and N atoms of the molecular structure.Under physiological conditions,the probe emits yellow aggregated fluorescence at 540 nm.When probe bonded to Al³⁺,blue fluorescence was observed at 430 nm.There were larger the Soxhlet shift,which was beneficial for bioimaging.Under the optimal experimental conditions,the detection limit of the probe toward Al³⁺was 0.4?M.In addition,the probe can detect Al³⁺in living cells.This method has the advantages of simple operation,low cost,high sensitivity and selectivity.?2?A novel double-Schiff base derivative as fluorescent probe was designed and synthesized for the detection of Hg²⁺by simple synthetic routes and mild experimental conditions,based on dialdehyde and 4-aminotriphenylamine.It can be used for the“naked eye”detection of Hg²⁺under 365 nm UV light irradiation,based the AIE feature of the probe.Under the optimized experimental conditions,the probe can detect Hg²⁺in water environment with high selectivity and sensitivity,and the detection limit of Hg²⁺was 0.077?M.In addition,the probe has good biocompatibility and low toxicity,which can be used to detect intracellular Hg²⁺.This study provides a new strategy for designing efficient AIE probes.?3?A salicylaldehyde-2-naphthylamine derivative as fluorescent probe was designed and synthesized for the detection of Zn²⁺.The probe exhibited AIE characterization,according to the study of photophysical properties.The detection of Zn²⁺was achieved,based on the heteroatoms in the molecular structure of the probe selective coordinated with Zn²⁺,which was not any interference from other common metal ions,especially Cd²⁺.Under optimized experimental conditions,the probe has a good linear response to Zn²⁺in the range of 0.1-30?M with a detection limit of 46 nM.In addition,based on the application of AIE molecular in solid film,the preparation and application of Zn²⁺test paper has been carried out.The method is simple and low cost.?4?A double Schiff base compound containing two Bis-?2-picolyl?amine?DAP?groups was designed and synthesized as fluorescent probe for the selective recognition of Zn²⁺.Further,with changing the proportion of the solvent,the fluorescence property of the probe toward Zn²⁺was changed.The detection of ssDNA was achieved by the metal coordination interaction between Zn²⁺and DNA,based on the AIE property of the probe.The establishment and research of this method provides a novel double fluorescence technique for detecting other metal ions and biomolecules in biological systems.