In this work, we have applied surface-enhanced Raman scattering (SERS) and surface-enhanced infrared
spectroscopy (SEIR) to study the interaction of nitro polycyclic aromatic hydrocarbons (NPAHs) with metal
surfaces. The nitro group confers the polycyclic aromatic hydrocarbons (PAHs) moiety additional electronic
and structural characteristics which verify NPAHs−surface interactions. SERS and SEIR spectra suggest that
the NPAHs 1-nitropyrene (1NP) and 2-nitrofluorene (2NF) at concentrations of <10-6 M (∼200 ppb) interact
with metal surfaces through the nitro group, adopting a perpendicular orientation onto the surface. In both
cases, the interaction seems to occur through the O atoms of the nitro groups, which are coplanar to the
PAHs fragment. The most efficient interaction was obtained using silver metal colloidal surfaces. The
mechanism of interaction with the metal surface is related to the structure of NPAHs: although a monodentate
interaction is deduced in the case of 1NP, a bidentate one seems to occur in the case of 2NF. To complete
this study, theoretical Raman vibrational spectra of both free 2NF and their complexes with silver metal
clusters were obtained using the local spin density approximation (LSDA) methods with the LAN12DZ basis
set. The theoretical calculations were compared to the experimental results, obtaining a good agreement with
the SERS and SEIR data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.