This compilation opens with a discussion on the state of the art of the most representative mesostructured materials based on silicon dioxide used in diverse applications, and focusing on the synthesis, functionalization, and characterization of such materials. Following this, the authors present examples of success in using polymeric nanoparticles, as well as methods for their formation and physicochemical analysis required prior to perform safety and efficacy biological tests. Various mechanisms of silver nanoparticles contribute to their cytotoxicity, including generation of reactive oxygen species, DNA damage, and activation of signaling events leading to inflammation, apoptosis, and necrosis. As such, the authors propose that future efforts be focused on the development of less toxic silver nanoparticles. Continuing, graphene and its by-products are defined and the mechanism of electromagnetic waves absorption via graphene-based substrates and nanocomposites is presented. Various kinds of graphene-based electromagnetic shields are examined and their performances compared. Physicochemical characterizations of the nanoemulsions are performed, including analysis over a period time to monitor the maintenance of these characteristics during storage. Next, a series of topics regarding electromagnetic wave shielding theory, sample fabrication methods, and characterization of the shielding materials are presented and experimental programs reported in the literature are reviewed. In conclusion, the authors present results of investigations concerned with the impact of rhodamine-B deposition on the surface of porous silicon on the chemical composition and optical properties of this system.