Fast detection of organic amine vapors based on fluorescent nanofibrils fabricated from triphenylamine functionalized β-diketone-boron difluoride

Nanofibrils emitting strong red light have been fabricated from triphenylamine functionalized beta-diketone-boron difluoride 1, via a rapid solution dispersion approach. It is found that the nanofibrils based on compound 1 can sense volatile organic amines and pyridine selectively. For example, the fluorescence of the nanofibril-based film can be quenched quickly and significantly upon exposed to the vapors of n-butylamine, dibutylamine, tributylamine, triethylamine, cyclohexylamine, hydrazine, aniline, N,N-dimethylaniline and pyridine instead of other common reagents. Notably, the response time of the nanofibril-based film to aniline is ca. 1.06 s, which is one of the fastest fluorescent responses to aniline. The detection limit of the nanofibril-based film for aniline vapor can reach ca. 100 ppb. We suggest that the high sensitivity and fast response of the sensory nanofibrils towards gaseous amines may come from the high surface-to-volume ratio and large interspace in the nanofibril-based networks, which favor the enhanced adsorption, accumulation and diffusion of gaseous molecules. In addition, the amplified fluorescence quenching induced by the enhanced intermolecular exciton diffusion along the long axis of the 1D nanostructures is another reason for the high performance of the obtained sensory nanomaterial.