Recent advances on the characterization of nanoparticles using infrared spectroscopy

Abstract Infrared (IR) spectroscopy provides highly discriminatory information due to the excitation of inherently specific fundamental vibrational transitions characteristic of molecular species. Nanoparticles of diverse nature have been characterized and determined using different spectroscopic techniques in the infrared range. Nanoparticles with inherent infrared absorptions or functional groups present at their surface may thus be directly characterized via infrared spectroscopy. Furthermore, different ligands attached to nanoparticles may readily be identified according to their vibrational signatures in a rapid, precise, and non-destructive way. Next to the direct characterization of such materials, some nanostructures modify the local optical field, thereby yielding enhanced IR signals facilitating advanced infrared imaging procedures for nanoparticles. In this review, recent examples for the characterization of nanoparticles and their surface functionalization via IR spectroscopy are discussed, and exemplary application examples including toxicological studies and adsorption processes are highlighted.