Localized Surface Plasmon Resonance Investigations\nof Photoswitching in Azobenzene-Functionalized\nSelf-Assembled Monolayers on Au

Abstract

Localized plasmon resonance (LSPR)\nspectroscopy, employing gold\nnanodisk substrates, is applied for studies of photoswitching in self-assembled\nmonolayers of azobenzene-containing thiols. By choosing customized\nsamples in which the sharp LSPR resonance is well separated from the\nspectral regime of the molecular absorption bands, the photoisomerization\nkinetics of the adlayer can be monitored in real time. Quantitative\ndata on the photoinduced trans<i>–</i>cis and cis<i>–</i>trans isomerization processes in inert gas atmosphere\nwere obtained as a function of irradiation intensity and temperature,\ndemonstrating the high sensitivity of this technique to such processes\nin functional adlayers.