Photofabrication of Chiral Plasmonic Nanostructure Arrays

Chiral plasmonic nanostructures can be potentially applied to chiroptical materials and devices, as well as sensors for chiral molecules. When those are applied to metasurfaces or metamaterials, those would be appropriately oriented and aligned. We therefore prepared arrays of chiral plasmonic nanostructures on the basis of bottom-up, self-assembling methods. A triangular Au nanoplate array as an achiral precursor was prepared on a TiO2-coated substrate by nanosphere lithography. The array was irradiated with right- or left-circularly polarized light (CPL) in a solution containing Pb2+ for site-selective deposition of PbO2 in a chiral geometry by plasmon-induced charge separation. The well-aligned Au-PbO2 nanostructure array thus obtained exhibits circular dichroism, and the handedness of the array can be inverted by changing the rotation direction of the irradiated CPL.

Automated summary

Chiral plasmonic nanostructures have potential applications in chiroptical materials, devices, and chiral molecule sensors. A bottom-up, self-assembling method was used to prepare arrays of these structures, which were then properly oriented and aligned. The resulting well-aligned gold-lead dioxide nanostructure array exhibits circular dichroism and can have its handedness inverted by changing the rotation direction of the irradiated circularly polarized light.