Self-assembly urchin-like Au-NSs arrays and application as surface-enhanced Raman scattering substrates

A simple and cost-effective approach has been exploited for the synthesis of large-area urchin-like Au nanospheres (Au-NSs) micro-nano arrays in anodic aluminum oxide (AAO) template. By sputtering Au on the surface of highly ordered Fe nanorods arrays, Au nanoparticles (Au-NPs) could self-assembly to form urchin-like micro-nano arrays. The urchin-like micro-nano arrays exhibit strong surface-enhanced Raman scattering (SERS) activity for detecting rhodamine 6G (R6G) because of its regular arrangement and rough surface. According to the analysis of three-dimensional finite-difference-time-domain (FDTD) simulations (Lumerical FDTD Solution, Inc., Canada), the strong SERS activity is mainly due to the high density of hot spots induced by the gaps between the neighboring Au-NSs. The Urchin-like arrays exhibit promising potential as new platforms to realize novel optoelectronic devices.