All-plasmonic-metal chiral nanostructures fabricated by circularly polarized light

Abstract

Chiral plasmonic nanostructures, which would be applied to enantioselective sensors and metasurfaces, can be prepared in an enantioselective manner by irradiation with circularly polarized light (CPL). However, their resonance sites have been covered with non-plasmonic, dielectric moieties. Here, we prepared all-silver chiral plasmonic nanostructures on a glass plate in one-step by irradiating 380-450 nm right- or left-CPL to an aqueous solution containing Ag+ and citrate ions. Achiral or racemic Ag nanoparticles with anisotropic geometry are deposited on a glass plate by photochemical electron transfer from citrate to Ag+ in the initial phase. The deposited nanoparticles are grown into chiral structures under CPL via generation of an electric field with chiral distributions. An achiral Ag nanoplate array was also grown under 600-700 nm CPL into chiral nanostructure arrays on the basis of hot electron reduction of Ag+