Reversible and selective sensing of aniline vapor by perylene-bridged bis(cyclodextrins) assembly.

Detecting volatile amines is a significant topic in quality control of food and medical diagnosis. Selectively sensing a given gaseous amine from other analogues, however, still remains a formidable challenge in solid-state fluorescence sensing because of the lack of specialized binding sites. Herein, we demonstrate a new supramolecular strategy for selectively sensing aniline based on the aggregation of perylene-cyclodextrin conjugate 1. Compared with our previous results based on perylene-bridged bis(permethyl-β-cyclodextrins), the present system achieves a pronounced improvement of both selectivity and reversibility. The sensory material was constructed from the π-stacking aggregate of 1 embedded in poly(vinylidene fluoride) membrane, which ensures benign solid-state fluorescence with potential amplification mechanism as well as convenient preparation and practical operation. Grafting cyclodextrin receptors endows the sensory material with desired selectivity as a result of diverse binding abilities. Especially, the thermodynamically reversible host-guest inclusion leads to the excellent sensing reversibility. The present research opens the way to build new n-type fluorescence sensory materials for detecting volatile amines instantly with compelling selectivity, sensitivity, and reversibility.