(363a) Solution-Based Fabrication and Application of Tunable Particles for Surface-Enhanced Raman Scattering

Vibrational modes in molecules provide unique Raman signals allowing these molecules to be detected with high specificity. Because Raman scattering is weak, Surface-enhanced Raman Scattering (SERS) has been used as a label-free technique for the detection of a variety of analytes at low concentrations. Using simple solution-based colloidal processing techniques, we have fabricated gold coated carbon black nanoparticles that show highly enhanced Raman activity. Variations in the processing conditions allow tuning of the peak in the local surface plasmon resonance (LSPR) wavelength. We show that the Raman signal coming from 4-nitrobenzenethiol is significantly enhanced when the LSPR peak wavelength matches the wavelength of the incident radiation driving Raman scattering. The ability to tune the LSPR of particles using simple solution-based processing expands the range of incident radiation wavelengths that can be used for detection of analytes using Raman scattering, concomitantly lowering of the limit of detection for analytes.