A nanostructure including a pair of pointed metallic tips in proximity to each other. The pair of pointed metallic tips protrudes from a planar top surface of a substrate by a pair of pillar structures. The pair of pointed metallic tips can enhance optical scattering of materials placed therebetween through plasmonic electromagnetic field effects induced by the proximity of the pair of pointed metallic tips. Perturbation or interference from the substrate can be minimized through the increased distance from the substrate. The pair of pointed metallic tips can be formed by patterning a pair of adhesion material portions on a substrate, by vertically and laterally recessing regions that are not covered by the adhesion material portions, and by depositing a metal on the pair of adhesion material portions.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This disclosure was made with United States government support under Prime Contract No. DE-AC05-00OR22725 awarded by the U.S. Department of Energy. The United States government has certain rights in this disclosure.