32‐Symmetric Chiral Gold Nanoplates with Near‐Infrared Circular Dichroism

Abstract Plasmonic chiral nanostructures provide a novel route for extraordinary optical properties, such as light polarization control and enhancing chiroptical signals of molecules. The symmetry of chiral nanostructures, such as helices, gyroids, and irregular tetrahedrons, is strongly correlated to chiroptical responses; therefore, it is an important design parameter. In a previous study, a synthetic strategy is demonstrated for 432‐symmetric chiral gold nanoparticles by breaking the mirror symmetry of a 4/ m 2/ m ‐symmetric crystal structure on a high‐index surface. Herein, the aim is to extend the chiral symmetry of gold nanoparticles and their chiroptical responses. The symmetry of gold nanoparticles can be modulated by inducing single or multiple twin planes in seed nanoparticles. The 32‐symmetric chiral gold nanoplates, referred to as 32 helicoids, are successfully synthesized us…