A supramolecular brush polymer Poly(P5-OXD) was constructed through the self-assembly of an A1/A2 disubstituted pillar[5]arene P5-OXD with a 1,3,4-oxadiazole unit and a cyanobutoxy group, exhibiting external stimuli responsiveness towards Cu2+ ions with an ON/OFF fluorescence signal output.
![Graphical abstract: Supramolecular brush polymers prepared from 1,3,4-oxadiazole and cyanobutoxy functionalised pillar[5]arene for detecting Cu2+](http://hg.y866.cn/compound/lib/scimg/usr/1/D0OB02587A.jpg)