Curvature sculptured growth of plasmonic nanostructures by supramolecular recognition

Abstract

Nanoscale curvature is an important and powerful tool in understanding and tailoring chemical/surface functionalities of nanostructures that dictate a host of important applications from biochemical recognitions, catalysis to spectroscopy. However, it is a critical challenge in materials chemistry to rationally shape the local nanoscale curvatures of colloidal nanoparticles during the growth owing to the constraints of their flat facets. Here we demonstrate a synthetic mechanism that could cooperatively mediate local nanoparticle surface curvature patchiness and shape symmetries during one-step colloidal growth. The idea is to tailor host-guest supramolecular recognition using fluorocarbon and hydrocarbon molecules that regulate interfacial energy during the nanoparticle growth. Such delicate regulation enables a degree of freedom in control over the local nanoparticle curvatures during the growth, resulting in intriguing plasmonic properties. More interestingly, a morphological shape transformation was induced by such curvature changes from anisotropic nanorods to isotropic nanospheres. This unique approach of the spontaneous curvature/structural transformation of plasmonic nanoparticles exploits the mutual interplay between competing supramolecules and colloidal growth. It may ultimately allow for accurate controlling nanoscale objects with varied degree of complexity that could open the door to a myriad of surface chemical, optical, and biomedical applications.