Engineering of Host–Guest Interactions To Tune the Assembly of Plasmonic Nanoparticles

Controlling the interaction between linking components and nanoobjects is expected to offer exciting new opportunities to induce tunable assembly and modulate the topology and properties of nanostructures. In this work, engineering the exclusive and inclusive host–guest interaction between cucurbit­[<i>n</i>]­urils and salts is demonstrated as a novel strategy to simultaneously realize tunable assembly of plasmonic nanoparticles (NPs) with controllable size and composition and manipulate the stability of the assemblies. As a proof of concept, one-dimensional nanochains of gold, silver, and their alloys with rigid subnanometer interparticle separation and widely tunable optical properties are generated. These exhibit strong dipole coupling between the plasmonic NPs, confirmed by experiments and theoretical simulations. This controllable assembly principle will lead to significant interest not only in supramolecular chemistry and the interactions between supramolecular and plasmonic NPs but also in interaction mechanisms and light management and light harvesting in advanced applications. It is also expected that our approach will be applicable to a wide range of NPs beyond plasmonic NPs with varied sizes and compositions