All spectroscopic experiments were performed using a Bruker IFS66v/s spectrometer equipped with a MCT photoconductive detector and a Kretschmann-ATR setup adjusted to an angle of incidence of 60°. For each spectrum, 400 scans were acquired in the spectral range of 4000 to 1000 cm -1 and at a spectral resolution of 4 cm -1 . Nanostructured Au films for SEIRA spectroscopy were produced by electroless deposition from an a NaAuCl4 solution according to Miyake et al.