Multiple internal reflection in surface enhanced infrared absorption spectroscopy (SEIRA) and its significance for various analyte groups

The presence of rough metal surfaces is known to increase the infrared absorption of selected analytes. It could be shown that this surface enhancement effect applies to a wide range of chemical substrates with different molecular structure, although the observed enhancement is not equivalent for all absorption bands. For carboxyl groups, interactions with the metal surface were observed suggesting the formation of an adsorption complex. Furthermore, the potential of surface enhanced infrared absorption (SEIRA) as quantitative method is demonstrated.