Covalent organic framework modified polyacrylamide electrospun nanofiber membrane as a “turn-on” fluorescent sensor for primary aliphatic amine gas

Covalent organic frameworks (COFs) for fluorescence sensing have been under intensive investigation recently because of their excellent molecule recognition and chemical sensing capabilities. However, the utilization of COFs-based sensors is limited by the arduousness in processing and forming. Herein, a composite material is designed based on the synergy effects, which use polyacrylamide (PAM) as a matrix and TFP-PPDA COF as reinforcement. PAM/TFP-PPDA composite nanofibrous membrane (NFM) is prepared combined with electrospinning technology. PAM/TFP-PPDA can effectively use fluorescence sensing of volatile organic compounds (VOCs) to achieve the specific detection of primary aliphatic amine on the fluorescence enhances (turn-on) effect. Significantly, a linear "turn-on" relationship is observed between PAM/TFP-PPDA and the amines over a wide range of concentrations. The donor-acceptor electron-transfer mechanism of "turn-on" responsive chemosensor is further investigated using molecular simulations and density functional theory (DFT) methods. This work expanded the use of new technologies in COFs composite molding and paved the way for developing fluorescence sensors for the gas response. • A COFs-based gas sensor was developed based on the “turn-on” fluorescence effect. • Electrospinning assisted the preparation of COFs modified composite nanofibrous membrane. • The specificity and sensitivity sensing for primary aliphatic amine were implemented. • Complementation of electron-transfer mechanism and dipole interactions were proposed.