Verifying electromagnetic first layer effect on surface enhanced infrared absorption with evaporated gold nano island film

Infrared absorption enhancement is reported for a polyacrylic acid film deposited on evaporated gold film in normal transmission geometry. Comparison between absorption intensities measured with and without the self-assembled monolayer of p-nitrothiophenol demonstrates that the absorption intensities of polyacrylic acid are independent of the presence of a self-assembled monolayer. Results suggest that the first layer effect in the physical enhancement mechanism does not exist in this thermally evaporated island film.