Design And Synthesis Of Novel Aggregation-induced Emission Small Molecules And Their Applications Research

In this thesis,a variety of novel AIE fluorescent molecules were successfully synthesized using simple organic reactions and studied in multiple fields such as ion detection,cell imaging,explosive identification,antibiotic detection,and latent fingerprint imaging.The details of the study are as follows:(1)Design and synthesis of AIE probe based on vitamin E derivatives for Fe3+ specificity detection.In this work,a novel probe VESA was synthesized by forming an amide bond between vitamin E succinate and 1-aminopyrene.Multiple characterization methods demonstrated that VESA had the significant AIE property and emitted blue-green fluorescence in the aggregated state in solution;VESA could form a complex with Fe3+ in the ratio of 1:1,which could cause quenching of its own fluorescence,resulting in a specific detection of Fe3+ with a minimum detection limit of 5.6×10-9 M.Cellular experiments demonstrated that this probe had low cytotoxicity and biocompatibility,which easily entered cells and emitted bright green fluorescence,and enabled the detection of exogenous Fe3+ at the cellular level,suggesting that VESA is a promising AIE ion probe for bioimaging applications.This work is the first to use vitamin E structure in the design and synthesis of AIE molecule,which proves that the introduction of natural active groups into the molecular structure of AIE can help reduce the cytotoxicity of the material,and provides a new strategy for the design of new AIE cell imaging materials.(2)Synthesis and application of AIE probe for highly selective detection of the explosive CL-20In this work,a novel AIE fluorescent molecule CSA was prepared using cholesteryl succinate and 1-aminopyrene,and CSA showed specific recognition characteristics for cage explosive CL-20 in interaction with a variety of explosives in tetrahydrofuran-water mixed solution,meanwhile this performance was not interfered by the presence of other explosives,and the probe CSA had excellent properties of fluorescence emission and explosive recognition in a wide pH range with a maximum quenching constant reaching 2.69 × 105 M-1.The special cage-like spatial configuration of CL-20 effectively encapsulated the CSA aggregates,and the electron transfer between them led to the quenching of the probe fluorescence.In addition to the rapid identification of CL-20,the special fluorescent sludge and swabs prepared by CSA have the potential to become special fluorescent markers and functional materials for encrypted information carriers.This work has realized the detection of CL-20 explosive by AIE fluorescent probe for the first time,which has certain practical significance to enrich AIE system and fill the gap in the field of new explosive probe.(3)Design and synthesis of novel AIE fluorescent probes based on tetraphenylene groups and their study in explosives detectionIn this work,new AIE fluorescent probes T1 and T2 were synthesized by the reaction of tetraphenylene derivatives with vitamin E succinate.As fluorescent probes,T1 and T2 could selectively identify the explosive FOX-7 by fluorescence quenching,where both quenching rates exceeded 90%,with quenching constants of 4.02 × 105 M-1 and 5.74 × 105 M-1,respectively,and the minimum detection limits of FOX-7 were 6.07 × 10-7 M and 4.24 × 10-7 M,respectively.Even though in the presence of multiple competing explosives,different anions and cations,as well as a variety of pH solutions and natural water samples,the probes still maintained fluorescence stability and specific identification of explosive FOX-7,which had strong practical application value.Using the fluorescence characteristics of the two probes under UV light and the sensitivity to explosives FOX-7,special filter papers and swabs with specific identification of explosives FOX-7 were designed,which provided the possibility of quick and easy identification of explosives in actual battlefield or in the natural water and had the practical significance for the study of portable explosives detection probes.This is the first time that AIE material is applied in the detection of explosive FOX-7,which provides theoretical basis and factual basis for the design,synthesis and mechanism research of new explosive probe.(4)Design and synthesis of novel ACQ and AIE fluorescent probes and their study in tetracycline detectionThe misuse of tetracycline has brought a new crisis to today’s environmental protection and human health,so a large number of materials have been developed for the detection and identification of tetracycline.However,the application of AIE materials to tetracycline has been less studied,and the related methods and mechanisms are still incomplete.The fluorescent molecules HC and HT were obtained by reacting luminescent group N-amino-4-hydrazino-1,8 naphthalimide,as a raw material,with p-chlorobenzaldehyde and[1-(4-formylbiphenyl)-1,2,2triphenyl]ethylene,respectively.Experiments demonstrated that the two molecules have the fluorescence characteristics of ACQ and AIE,respectively,and their fluorescence can be quenched by tetracycline for the purpose of detection,with the lowest detection limits of 1.23×10-6 M and 1.33×10-6 M,respectively.As tetracycline probes,both molecules showed strong stability against interfering factors such as pH,other competing antibiotics,anions and cations,and could be used for quantitative detection of tetracycline in milk,urine and washing wastewater.AIE fluorescent molecule HT has low cytotoxicity and good biocompatibility for cytoplasmic imaging.(5)Design and synthesis of a novel AIE molecule and its application in TNT detection and latent fingerprint imagingNovel latent fingerprint imaging has been one of the popular researches.In this work,a novel AIE molecule CD1 was synthesized from 7-methoxy-2h-chromene-3-carbaldehyde and 1-acetyl-2-naphthol,which started to display fluorescence enhancement behavior in dimethyl sulfoxide solution with 80%water content and the highest fluorescence intensity in dimethyl sulfoxide solution with 99%water content.Four inorganic materials(chlorite,hydrotalcite,kaolinite,sodium montmorillonite)were used to demonstrate the feasibility of the inorganic material@AIE molecular composite for latent fingerprint imaging by compositing them with tetraphenylene molecules.The chlorite@CD1 composite with a mass ratio of 1:5 was screened as the optimal material for latent fingerprint imaging in this work,which can be used for fingerprint imaging of a variety of substrate materials and provides a new idea for the future development of latent fingerprint powder imaging materials.In addition,as a fluorescent probe,CD1 can also qualitatively and quantitatively detect explosive TNT with a quenching constant of 0.22×105 M-1 and a minimum detection limit of 1.1×10-5 M,making it "multi-purpose".