Synthesis of three-dimensional honeycomb-like Au nanoporous films by laser induced modification and its application for surface enhanced Raman spectroscopy

We report on the fabrication of three-dimensional (3D) Au nanoporous films with pores the size of ~200nm by laser-induced modification of as-prepared Au flat films. The construction of honeycomb-like Au porous structures should be attributed to a model of subsurface micro-explosive boiling followed by laser irradiating of Au flat films. The 3D honeycomb-like Au nanoporous films with unique interconnected frameworks exhibit ultrahigh surface enhanced Raman scattering (SERS) activity with an enhancement factor up to ~109 and excellent stability/reusability even after 300 cycles of repeated SERS analyses. The project of wielding laser light as a versatile tool for sculpting stable nanoporous films will prompt the renewed interest in the multi-functional nanomaterials.