Self-assembly And Application Of Organic Fluorescence Sensing Materials

Organic supramolecular assembly is a common and efficient method for preparing nanomaterials.The core of the method is to realize the ordered arrangement of molecules by the interaction of non-covalent bonds.Up to now,nanostructured materials self-assembled from organic supramolecules have been widely used in many fields,such as materials,biology,electronics,medicine and so on.Perylene imide and its derivatives are n-type semiconductors with stable optical and electrical properties,which are widely used in organic optoelectronic devices.Nanomaterials with different morphologies and properties,such as nanofibers,nanohelices,and nanoribbons,can be prepared by changing the side chains and substituents on the backbone of perylene imide molecules.Hydroperoxide peroxide-based explosives such as triperoxide triacetone(TATP)have been increasingly used for terrorist activities and other crimes against public security,because the starting materials of TATP,i.e.,acetone,hydrogen peroxide,and acid are all commercially available in pharmacies and reagent companies,and the synthetic process of TATP is very simple and available on the internet.However,because it lacks nitro or aromatic groups,it cannot be detected by common UV absorption or fluorescence spectroscopy.Among the methods for TATP detection,fluorescent sensors have attracted wide attention due to their low cost,portability and high sensitivity.However,the current fluorescence sensor for detection of gaseous TATP is rarely studied.Sarin is a highly toxic chemical warfare agent.Fluorescence detection of sarin has been widely concerned,but highly sensitive and selective detection have not been achieved.In this work,we report the self-assembly of perylene imide molecules and characterize their fluorescence properties.Firstly,the self-assembly process of an azo group-modified perylene imide molecule was studied,and the evolution of the morphology during the process was discovered.Then by studying the self-assembly of a series of perylene imide derivatives with different structures,we find that some structural parameters have a critical impact on the morphology.Different molecular structures,such as the position of substituents on benzene,the linker between substituted benzene and perylene imides,and the length of hydrophobic chains on perylene imides,have different effects on the morphology of the materials.These nanomaterials have also been used for fluorescence detection of DCP,a neurotoxic analogue of sarin.Finally,the nanofibers-amberlyst-15 blend was successfully used to detect TATP with high sensitivity and selectivity,and the detection mechanism was studied to make the practical application of the material possible.