Hybrid plasmonic nanoparticle assemblies with tunable properties for biophysical applications

In recent years nanoplasmonics has attracted increasing scientific interest arising from the possibility of manipulating the optical phenomena at the interface of nanostructured materials. Indeed, advances in nanofabrication techniques enabled for tailoring and enhancing electromagnetic fields at the sub-wavelength scale, opening to a wide range of applications in different scientific contexts, spreading from electronics to biomedicine. Among the different nanoarchitectures available, a relevant position is occupied by systems made of nanoparticles (NPs) of noble metals such as gold and silver. This Ph.D. Thesis is aimed at addressing the design of plasmonic nanostructures with the desired optical and biological properties. The general idea is to reach a strict control on the spatial organisation and surface properties of gold NP assemblies for mastering the plasmon coupling and the interaction with the external environment. Efforts have been made in quantitatively framing the presented studies in the context of nanoplasmonics theory, and in developing interpretative models for the specific phenomena studied. The results were supported by biological investigation with the purpose of providing a strong scientific background in transferring the obtained findings towards the development of novel biophysical strategies.