Localized surface plasmon resonance of nanoporous gold

We report the plasmonic properties of free-standing nanoporous gold (NPG) films with an intricate bicontinuous nanostructure. Two characteristic plasmon bands of NPG have been detected in absorption spectra. One at ∼490 nm, resulting from the resonant absorption of gold films, is independent of nanopore sizes and dielectric surroundings. The other at ∼550–650 nm, arising from the excitation of localized surface plasmon resonance, shows obvious...