Large surface enhanced Raman scattering enhancements from fracture surfaces of nanoporous gold

Abstract

We report the improved surface enhanced Raman scattering (SERS) of mechanically ruptured nanoporous gold. The SERS intensities of rhodamine 6G and crystal violet 10B molecules from the fracture surfaces of nanoporous gold are about one order of magnitude higher than those from the as-prepared samples. Microstructural characterization reveals that the fracture surfaces contain numerous sharp protrusions with 5-10 nm apexes, produced by localized plastic deformation of gold ligaments during failure. The large SERS enhancements from the fracture surfaces are most likely associated with the intensified electromagnetic fields around the nanosized protrusions and the electromagnetic interaction between the protrusions. © 2008 American Institute of Physics.