Surface-enhanced Raman scattering on gold and aluminum particle arrays

Area of Science:

• Surface-enhanced Raman scattering (SERS)
• Plasmonics
• Nanophotonics

Background:

• Surface-enhanced Raman scattering (SERS) is a sensitive technique for molecular detection.
• The underlying mechanism is primarily attributed to localized surface plasmon resonances (LSPRs) in metallic nanostructures.
• Understanding the factors influencing SERS enhancement is crucial for optimizing its application.

Purpose of the Study:

• To investigate the dependence of SERS intensity and excitation wavelength on gold and aluminum surfaces.
• To compare the SERS enhancement factors of gold and aluminum with those of silver.
• To validate particle-plasmon theories in explaining SERS phenomena on different metallic nanostructures.

Main Methods:

• Fabrication of microlithographic gold, aluminum, and silver nanoparticle surfaces.
• Measurement of surface-enhanced Raman scattering (SERS) spectra.
• Systematic variation of excitation wavelength and analysis of intensity dependence.

Main Results:

• The intensity and excitation wavelength dependence of SERS were successfully measured on gold and aluminum surfaces.
• Observed SERS enhancement on gold and aluminum showed good agreement with theoretical predictions based on particle-plasmon theories.
• Comparative analysis with silver surfaces confirmed the validity of the theoretical models across different noble metals.

Conclusions:

• Particle-plasmon theories accurately describe the SERS enhancement on gold and aluminum nanoparticles.
• Microlithographically prepared metallic nanoparticles are suitable platforms for studying SERS.
• The findings support the use of plasmonic theories for designing and optimizing SERS substrates.