Preparation Of Fluorescent Sensing Materials And Their Application In Detection Of Organophosphorus Toxicants

Organophosphorus poisons have strong neurotoxicity,which poses a serious threat to human health and social safety.Therefore,the development of real-time rapid detection technology for organophosphorus poisons is not only of great scientific significance,but also in line with the actual needs of national security.Fluorescence sensing method has the advantages of convenience,high efficiency,simple operation,high sensitivity and low detection limit,which meet the development requirements of real-time rapid detection of organophosphorus poisons.However,it has some problems,such as long sensing response time,poor recovery and difficulty in identifying different phosphorus compounds.In order to solve these problems,this paper will enrich the application of fluorescence sensing in the detection of organophosphorus poisons from the perspectives of preparation of fluorescent materials,composite modification of materials and optimization of data processing methods.The following three aspects of research work are mainly carried out:In the second chapter of this paper,we synthesized a perylene bisimide derivative.The self-assembly characteristics of the aggregates were studied by controlling the evaporation rate of solvent.The optical anisotropy of the aggregates was investigated by polarizing microscope.The perylene imide derivative composite fluorescent nanofibers were successfully fabricated by electrospinning.The perylene imide aggregates arranged orderly in the nanofibers,and the composite nanofibers showed obvious optical anisotropy.By investigating the sensing response of the prepared fluorescent nanofibers to organic amines,it can be seen that the composite nanofibers prepared by electrospinning have faster response speed and shorter recovery time than those prepared by direct preparation of perylene imide aggregate lamellae and perylene imide polymer composite membranes.In order to overcome the long response time and recovery time of fluorescent sensing method in detecting organophosphorus toxicants,the composite nanofibers prepared by electrospinning have better response speed and shorter recovery time.This method provides a new way for overcoming the problems including long time and poor recovery of fluorescent sensing in detecting organophosphorus toxicants.In the third chapter,four new perylene imide fluorescent probes were designed and synthesized for the detection of organophosphorus poisons.The fluorescence sensing behavior of the probes for Sarin simulant diethyl chlorophosphate(DCP),was investigated by fluorescence titration in solution.In addition,by investigating the anti-interference performance of fluorescent probes,it was found that the probes were insensitive to common organic solvents,other organic phosphorus and organic acids,and showed good selectivity.Based on the results of Chapter 2,fluorescent nanofibers with probe compounds were fabricated by electrospinning.Gas sensing experiments were carried out to investigate the sensing properties of nanofibers for DCP vapor.The fluorescence response time of nanofibers to DCP vapor is no more than 3 seconds,and it can recover quickly in 6-9 seconds with air sweeping.Multidimensional sensor array combined with principal component analysis(PCA)has important value for the research and application in the recognition and differentiation of complex components.The sharp emission peaks of rare-earth fluorescent complexes can produce fluorescent response to various organophosphorus poisons,which can effectively compensate for the poor differentiation of perylene bisimide.In the fourth chapter,we synthesized two rare-earth fluorescent complexes to construct fluorescent sensor arrays for recognition and differentiation of organophosphorus poisons.The significant differences of different organophosphorus poisons on the fluorescence sensor array were investigated by fluorescence titration experiments.Further PCA was used to analyze the difference signals,which realized the recognition and differentiation of organophosphorus poisons successfully.