Transient cucurbit[7]uril-mediated host-guest complexes for time-dependent fluorescence and information-self-erasing hydrogel.

A non-equilibrium cucurbit[7]uril-mediated supramolecular host-guest system is fabricated by using urea/urease to control aqueous solution pH on time dimension, showing transient assembly behavior and time-dependent fluorescence. The dynamic assembly can be also achieved in hydrogel network, resulting in a time-dependent fluorescent hydrogel for information encryption.