Gold Nanoarrow-Based Core–Shell and Yolk–Shell Nanoparticles for Surface-Enhanced Raman Scattering

Precise control over the structure and morphology of core–shell and yolk–shell plasmonic nanoparticles is crucial to the realization of the desired plasmonic properties and promising applications. In this work, uniform arrow-shaped and cuboidal GNA@Ag core–shell nanoparticles were prepared via seed-mediated epitaxial growth, and the subsequent galvanic replacement combined with coreduction led to the formation of unique arrow-shaped and cuboidal GNA@AuAg yolk–shell nanoparticles. The obtained GNA@Ag nanoparticles and GNA@AuAg nanorattles show distinct plasmonic absorption features. The GNA@AuAg nanorattles exhibit an excellent solution-based SERS sensing capability due to the existence of rich intragaps and sharp features, with the arrow-shaped nanorattles showing superior performance.