Fig. 2: Comparison of low-frequency modes.
From: Uncovering low-frequency vibrations in surface-enhanced Raman of organic molecules
a, c Low- and high-frequency SERS Stokes spectra of seven molecules forming SAMs inside 80 nm Au NPoMs. Representative spectra were selected from several hundred NPoMs (see text). ERS bosonic background is fit and subtracted by process detailed in Supplementary Note 2. b Thirty low-frequency spectra of each molecule clustered and projected using PCA. The Marker area is coloured according to the true label of molecules (1–7), and the edges are coloured according to their cluster label (see text).
