Engineering versatile SERS-active nanoparticles by embedding reporters between Au-core/Ag-shell through layer-by-layer deposited polyelectrolytes

We report a new strategy to engineer versatile SERS-active nanoparticles by embedding Raman reporter molecules inside Au-core/Ag-shell nanoparticles through layer-by-layer deposition of polyelectrolytes. The results demonstrate a class of core-shell nanoparticles that can find use as SERS-tags for Raman-based assays and imaging with strong SERS signals, versatility and simplicity in synthesis, and good stability. The strategy may also be useful to the preparation of plasmonic nanostructures for other purposes.