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 band shift with the nanopore sizes and dielectric indices of surrounding media, suggesting that NPG is a promising candidate as plasmonic sensors for organic and biologic molecule detection. This study also shines light on the underlying mechanisms of surface enhanced spectroscopy of NPG.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)