Our research aim is to control the optical properties of mesostructured assemblies by using rational design, self-assembly methods in combination with tailored plasmonic building blocks and optical characterization methods. Optical metasurfaces are artificially structured materials, which have a controlled heterogeneity on a length scale less than the wavelength of light. By using a rational design we can control the interaction of light with the nanostructured material, which leads to unprecedented functionalities. The tailored optical properties are of interest for a broad academic and industrial community for possible applications in the field of energy production (light harvesting, light concentrators), information technology (manipulation of light flow and storage, logic photonic circuits), stealth (optical cloaking, negative refractive index), and life sciences (physical and chemical sensing). There are well-established approaches for guiding the flow of light and tailoring its reflection using optical metasurfaces. However, this material class is limited by its elaborated top-down fabrication methods such as e-beam lithography or ion-beam milling (losses due to polycrystallinity, lack in resolution and scalability). Building up on those, we are using template-assisted self-assembly methods (bottom-up techniques) to obtain scalable mesostructured materials. Our research is dedicated to electromagnetic modeling, fabrication and characterization of novel functional system materials based on a unique combination of plasmonic and quantum emitter materials. We aim the creation of tailored system materials, by employing the interaction of different components, such as nanoparticles, nanostructures and functional polymers.