Ordered mesoporous silver superstructures with SERS hot spots

We have developed a method to fabricate freestanding highly ordered porous silver (Ag) superstructures by “assembly-based nanoparticle (NP) coalescence” method. The synthesized superstructures have high-density mesopores periodically distributed over the entire structure, on which highly enhanced electromagnetic field was observed by electron energy loss spectroscopy. Thus, the surface enhanced Raman scattering (SERS) signal of Rhodamine 6G in the ordered mesopore is 8.2 times higher compared to that in the disordered porous superstructures. The results demonstrate that these freestanding mesoporous Ag superstructures are potentially good SERS substrates.