Fabrication of gold flower-like arrays based on nanosphere lithography for Raman enhancement

Gold flower-like nanoarrays based on nanosphere lithography (NSL) have been fabricated for Raman enhancement. After spin-costing of 509 nm polystyrene nanosphere and O2 etching of the substrate, deposition and annealing make the gold nanoarrays bulging, forming the flower-like nanoarrays. FDTD simulation of the nanostructures shows that these nanoarrays show high electromagnetic enhancement. Main enhancements are on the edges of the substrate. At last, Raman tests using Rhodamine 6G indicate that these nanoarrays show high Raman intensity when comparing with that of Au substrate. Minimum Rhodamine 6G detection limit of these arrays can reach the level of 10-6 mol/L.