Formation of cyanide compounds during preparation of gold surfaces evidenced by surface‐enhanced Raman spectroscopy

Alexandre Merlen (1) , Cedric Pardanaud (2) , Stéphane Coussin (2) , Christos Panagiotopoulos (3) , Olivier Grauby (4) , Carmen Ruiz (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 PIIM - Physique des interactions ioniques et moléculaires
3 MIO - Institut méditerranéen d'océanologie
4 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille

We report Surface Enhanced Raman Spectroscopy (SERS) measurements on nanostructured gold surfaces prepared using a primary vacuum sputtering technique. Even if no molecules have been deposited on the metallic surface a clear Raman signal is observed. A very intense and sharp peak around 2100 cm-1 together with low frequency modes are visible. The comparison between the experimental spectra and those obtained using Density functional theory (DFT) calculations confirms that these new modes are associated to the cyanide compound Au(CN)2-. This proves the high sensitivity of SERS for the chemical analysis of metallic surfaces. It also shows that the pollution should be carefully taken into account in SERS analysis. We also demonstrate that high power laser illumination transform these toxic compounds into carbon species, this method can be used to clean SERS substrates.

Mots clés: cyanide compounds; gold; surface-enhanced Raman spectroscopy

Domaines: Chimie analytique; Matériaux

Alexandre Merlen, Cedric Pardanaud, Stéphane Coussin, Christos Panagiotopoulos, Olivier Grauby, et al.. Formation of cyanide compounds during preparation of gold surfaces evidenced by surface‐enhanced Raman spectroscopy. Journal of Raman Spectroscopy, 2018, pp.1-6. ⟨10.1002/jrs.5365⟩. ⟨hal-01770401⟩