Surface-enhanced resonance Raman scattering of adsorbates under liquid nitrogen

We compare the room temperature surface-enhanced resonance Raman scattering (SERRS) spectra of three molecules (riboflavin, 1-nitropyrene, and rhodamine 6G) adsorbed on rough silver films with SERRS spectra of the same samples submerged in liquid nitrogen. We find that the spectra obtained in the liquid nitrogen environment exhibit substantially higher signal-to-noise ratios, which we attribute to an increase in the SERRS electromagnetic enhancement factor in the liquid nitrogen environment arising from the dielectric properties of liquid nitrogen.