Strong Chiroptical Activities in Gold Nanorod Dimers Assembled Using DNA Origami Templates

Abstract

Asymmetric three-dimensional (3D) nanoarchitectures that cannot coincide with their mirrored-symmetric counterparts are known as chiral objects. Numerous studies have focused on chiral plasmonic nanoarchitectures created intentionally with 3D asymmetric configurations, whose plasmonic chirality is promising for various nanoplasmonic and nanophotonic applications. Here, we show that gold nanorod (AuNR) plasmonic nanoarchitectures assembled on a soft 2D DNA origami template, which was often simplified to be a rigid rectangle, can exhibit strong chiroptical activities. The slight flexibility of the origami templates was found to play a critical role in inducing the plasmonic chirality of the assembled nanoarchitectures. Our study set a new example of reflecting the native conformation of nanostructures using chiral spectroscopy and can inspire the exploration of the softness of DNA templates for the future design of assembled chiral nanoarchitectures.