Surface Enhanced Raman Spectroscopy (SERS) with silver-coated opaline structure. A suspension with CNT is placed on the platform. The Raman signature of SWCNT clearly appears when the sample is tilted such that surface plasmons are excited (25o in this example).
Similarly, one may explore enhanced Raman scatterings with array of holes.
Left: An array of holes in anodized aluminum oxide. The hole pitch was 90 nm. Right: The peak intensity is increased when the sample is tilted. Shown are two Raman lines from B. subtilis (a known Anthrax simulant). The inset exhibits Raman peak enhancement for SWCNT.