Excellent surface enhanced Raman scattering obtained with nanoporous gold fabricated by chemical de-alloying

Three dimensional nanoporous gold, with an average ligament size of 50 nm, was fabricated by chemical de-alloying from a new Au based metallic glass precursor. The resultant nanoporous gold gives rise to superior surface enhanced Raman scattering (SERS) capability using 4,40-bi-pyridine as probe molecules. The SERS intensity mapping images confirm the presence of hot spots. A low detection limit down to 10 (14) M for bipyridine was achieved, which is attributed to the localized enhanced electromagnetic fields around nano-sized ligaments, the electromagnetic coupling between ligaments, and the trapped SERS sensitive atoms. (C) 2016 Elsevier B.V. All rights reserved.