Graphene,
with its unique properties including atomic thickness,
atomic uniformity, and delocalized π bonds, has been reported
as a promising alternative material versus noble metals for surface-enhanced
spectroscopies. Here, a simple and effective graphene-enhanced infrared
absorption (GEIRA) strategy was developed based on infrared attenuated
total reflection spectroscopy (IR-ATR). The IR signals of a broad
range of molecules were significantly enhanced using graphene-decorated
diamond ATR crystal surfaces versus conventional ATR waveguides. Utilizing
rhodamine 6G (R6G) as the main model molecule, the experimental conditions
were optimized, and potential enhancement mechanisms are discussed.
Aqueous sample solutions were directly analyzed utilizing graphene
dispersions, which eliminates harsh experimental conditions, tedious
sample pretreatment, and sophisticated fabrication/patterning routines
at the ATR waveguide surface. The GEIRA approach presented here provides
simple experimental procedures, convenient operation, and excellent
reproducibility, promoting a more widespread usage of graphene in
surface-enhanced infrared absorption spectroscopy
