Interaction of azobenzene containing surfactants with plasmonic nanoparticles The goal of this thesis is related to the question how to introduce and combine simultaneously plasmonic and photoswitching properties to different nano objects. In this thesis I investigate the complexes between noble metal nanoparticles and cationic surfactants containing azobenzene units in their hydrophobic tail employing absorption spectroscopy surface zeta potential and electron microscopy. In the first part of the thesis the formation of complexes between negatively charged laser ablated spherical gold nanoparticles and cationic azobenzene surfactants in trans conformation is explored. It is shown that the constitution of the complexes strongly depends on a surfactant to gold molar ratio. At certain molar ratios particle self assembly into nanochains and their aggregation have been registered. At higher surfactant concentrations the surface charge of nanoparticles turned positive attributed to the formation of the stabilizing double layer of azobenzene surfactants on gold nanoparticle surfaces. These gold surfactant ...