Gold nanoparticle capping layers: structure, dynamics, and surface enhancement measured using 2D-IR spectroscopy.

Surface analysis: two-dimensional infrared spectroscopy (2D-IR) was used to probe amide and carboxylate functional groups in the vicinity of gold nanoparticles and their aggregates. The data presented shows that the unique ability of 2D-IR spectroscopy to characterize broadening mechanisms and cross peaks offers new insights into gold nanoparticle capping layer structure and dynamics.