Facile synthesis of ultrathin worm-like Au nanowires for highly active SERS substrates

In this report, ultrathin worm-like Au nanowires were constructed with the assistance of L-glutamic acid as a structure-directing agent and a weak stabilizing agent. The morphology of the Au products was found to be strongly dependent on the experimental parameters such as the amount of L-glutamic acid, as well as the reaction temperature. This synthesis was a seedless process, without using any template, surfactant, or toxic organic agent. Furthermore, the as-prepared Au nanowires were applied to facilely fabricate porous Au films with controllable thickness via simple gravity settling. The Au films showed high surface-enhanced Raman scattering (SERS) enhancement, using 4-mercaptobenzoic acid as a model probe. The Au films may be promising candidates for SERS sensing. This strategy provides an environmental friendly way for the preparation of various metal nanostructures with novel morphologies and useful applications.