Fast, Simple, Combinatorial Routes to the Fabrication of Reusable, Plasmonically Active Gold Nanostructures by Interferometric Lithography of Self-Assembled Monolayers

We describe a fast, simple method for the fabrication of reusable, robust gold nanostructures over macroscopic (cm2) areas. A wide range of nanostructure morphologies is accessible in a combinatorial fashion. Self-assembled monolayers of alkylthiolates on chromium-primed polycrystalline gold films are patterned using a Lloyd’s mirror interferometer and etched using mercaptoethylamine in ethanol in a rapid process that does not require access to clean-room facilities. The use of a Cr adhesion layer facilitates the cleaning of specimens by immersion in piranha solution, enabling their repeated reuse without significant change in their absorbance spectra over two years. A library of 200 different nanostructures was prepared and found to exhibit a range of optical behavior. Annealing yielded structures with a uniformly high degree of crystallinity that exhibited strong plasmon bands. Using a combinatorial approach, correlations were established between the preannealing morphologies (determined by the fabricat...