Nanotransfer printing of gold disk, ring and crescent arrays and their IR range optical properties

Abstract

We demonstrate a facile method to fabricate gold plasmonic microstructures based on the combination of colloidal lithography and a nanotransfer printing method. Poly(dimethylsiloxane) PDMS hemisphere arrays were fabricated through colloidal lithography and used as a “stamp” for the nanotransfer printing. Three kinds of plasmonic microstructures, gold disk, ring and crescent arrays, were fabricated by transferring gold “ink” onto the PDMS stamp, then to the substrate based on covalent “glue”. By adjusting the pressure applied during the printing process, the diameter of the as-prepared gold disks and gold rings can be precisely controlled, and these plasmonic arrays all exhibited significant diameter dependent LSPR properties in the NIR or Mid-IR range. In addition, by obliquely depositing gold ink onto the PDMS stamp, a gold crescent array with asymmetrical geometry was also prepared on the substrate. Owing to the asymmetric structure of the gold crescents, the gold crescent array showed significant polarization dependent LSPR properties in the Mid-IR range. We believe that these as-prepared gold plasmonic microstructures could show promising potential for application as real-time, label-free plasmonic sensing platforms in the IR range.