Synthesis and Characterization of Core-Shell Fluorescent Nanoparticles with Magnetic and Plasmon Properties, for Bio-Distribution Studies and Application In Photo-Ablation Cancer Therapy

The development of bimetallic/bifunctional nanoparticles that exhibit a core-shell architecture has been the focus of attention in recent years due to their unique properties in “anti-cancer therapy’’ and other potentially attractive applications. This study presents results on the synthesis and potential application in photo-ablation cancer therapy of a set of core-shell bifunctional gold-coated Silica spheres with both magnetic and plasmonic properties. Naked magnetite-maghemite Fe₃O₄-Fe₂O₃ nanoparticles are covered with a thin shell of silica using the well-known method developed by Stöber with some modifications. The silica-modified (magnetite-maghemite) nanoparticles are then functionalized with Silane (APES) monolayers which are subsequently covered with a thin solid shell using Au nanoparticles as seeds to template the growth of the shell. Also SiO₂@Au, and Fe₃O₄-Fe₂O₃@Au have been synthesized with the purpose of studying their plasmon properties; in the SiO₂@Au particles the silica core has been prepared ​​by a novel procedure using amino-acids as catalysts. The particles are characterized by X-ray diffraction(XRD), Dynamic Light Scattering (DLS), Zeta potential, Scanning Electron microscopy (SEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), and UV-VIS-NIR spectroscopy. Preliminary results on bio-distribution (in-vitro assays) and photo-thermal ablation activity (on a prototypical tissue) will also be presented.