Engineering stable plasmonic nanostructures for SERS applications

PHYS 40

Maryuri Roca and Amanda J. Haes. Department of Chemistry, University of Iowa, Iowa City, IA 52242
Synthesis of homogeneous nanostructures is required for the realization new technologies based on their novel properties. For instance, the optical properties of noble metal nanoparticles exhibit localized surface plasmon resonance bands that depend on their size, shape, and local dielectric environment. Nanoparticles that exhibit these novel properties can be synthesized via salt reduction methods and are inherently unstable because of the high surface energy of the structures coupled with poor electrostatic screening between individual nanoparticles. Environmental changes in pH, temperature, and ionic strength further decreases nanoparticle stability causing irreversible aggregation. In this presentation, we prevent the aggregation of noble metal nanoparticles by varying the surfaces with porous dielectric shells. The resulting structures are highly stable and retain the novel plasmonic properties of the metal core. Finally, we will demonstrate that these structures can be used as substrates for surface-enhanced Raman scattering (SERS) applications.