Development Of Novel Aiegens And The Investigation Of Structure-property Relationship

Traditional organic luminescent materials have the problem of aggregation-caused quenching(ACQ)at the aggregate state,which restricts their wide application in the field of biotechnology to some extent.Aggregationinduced emission(AIE)effectively overcomes the ACQ problem of traditional luminescent materials.With the further research on AIE materials,AIE materials have been widely used in various fields of science and technology.However,the current research on regulating the performance of AIE materials mainly focuses on the molecular structure design,and there are few reports on the relationship between the aggregation microenvironment and the properties of AIE materials.In view of this,the research content of this paper is as follows:We designed and synthesized di(N,N-dimethylaniline)-dibenzofulvene(NFTPE)with AIE activity.The influence and regulation of the aggregation microenvironment in crystal materials on the luminescence properties of AIE materials were studied.NFTPE exhibits obvious crystalline-induced emission enhancement(CIEE)effect,and has two different crystal structures,yellow and orange fluorescence emission,respectively.Single crystal analysis and density functional theory(DFT)calculations show that different aggregation microenvironment lead to different molecular conformation,which leads to different fluorescence emission of the two crystals.What is exciting is that with the assistance of the PEG polymer matrix,the crystallization process of NFTPE in aqueous solution could be monitored in situ by fluorescence changes.Therefore,the preparation of NFTPE nanocrystals(NFTPE-NCs)could be promoted by adjusting the aggregation microenvironment.The prepared NFTPE-NCs exhibit excellent luminescent properties and have potential application value in cell imaging.We designed and synthesized polymerizable AIE monomer TPE-1VBC to obtain fluorescent polymer nanoparticles(FPPs)through polymerization reaction,and studied the influence and regulation of the aggregation microenvironment in polymer matrix on the luminescence properties of AIE molecules.Firstly,we used maleic anhydride(MAH),styrene(St),AIE active TPE-1VBC as comonomers,which was initiated by 2,2-azobisisobutyronitrile(AIBN)in ethyl butyrate.Secondly,through the real-time monitoring of the formation process of FPPs,the influence of microenvironment in FPPs on the luminescence properties of AIE molecules was studied.The results showed that the dynamic hardening phenomenon existed during the formation of FPPs,which resulted in the increase of AIE molecular distortion and blue shift of luminescence.Moreover,the increase of the crosslinking degree of FPPs would further intensify the dynamic hardening effect.The luminescence properties of AIE materials could be regulated by adjusting the polymer matrix microenvironment.The prepared FPPs have the advantages of uniform and controllable size,high luminous efficiency,easy surface functionalization,which can be used as an indicator for fluorescent lateral flow assay(FLFA)testing strips.In addition,with the COVID-19 antibody as the target,verify the feasibility of FPPs@210 for FLFA.