A facile synthesis of dynamic supramolecular aggregates of cucurbit[n]uril (n=5-8) capped with gold nanoparticles in aqueous media.

Supramolecular capping of cucurbit[n]uril (CB[n]), where n=5-8, by narrowly dispersed gold nanoparticles has been achieved through a facile synthetic route with metastable gold nanoparticles as a labile intermediate. The resultant assemblies were stable in solution, and were found to form dynamic aggregates consisting of a controllable ratio of singly and doubly capped CB[n]. The stability of the system was attributed to the presence of sodium cations bound on the vacant carbonyl portals of the singly capped CB[n] molecules. These dynamically capped CB[n] systems can find potential use in a range of applications varying from ultrasensitive multiplexed in situ sensing to photocatalysis.