Magnetoplasmonic nanoparticles for photothermal therapy

Magnetoplasmonic nanoparticles for photothermal therapy Following the urge to obtain new "smart" nanomaterials, the application of nanotechnology to medicine (nanomedicine) is developing towards new employments of great impact. This is the case of hyperthermia, where superparamagnetic and plasmonic nanoparticles are investigated as nanoheaters or nanotransducers, which can be activated remotely by radiations minimally harmful to physiological tissue and fluids. Furthermore, iron oxide - gold/silver nanocomposites offer the combination of the unique features of both gold/silver and iron oxide nanomaterials to enable applications in diagnostic and therapeutic environments. In this work, a detailed study of the aqueous synthesis of iron oxide - gold/silver nanocomposites is presented. This method uses citric acid as stabilizing agent and (3-aminopropyl)triethoxysilane (APTES) for the dual functions of attaching fine gold and silver nanoparticles onto the magnetite surface as well as preventing the formation of aggregates. The reduction of the metal nanoparticles was achieved thanks to tannic acid. In addition, the possible further applicability of tannic acid as stabilizing agent is analyzed. Morphology, structure, composition and stability were characterized with Transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and ζ potential. Magnetic and optical properties were analyzed with vibrating sample magnetometry (VSM) and ultraviolet – visible spectroscopy. These structures maintained the optical and magnetic features of gold/silver and iron oxide nanoparticles.