(648c) Hybrid Magnetic-Plasmonic Nanoparticles for Biomarkers

Hybrid magnetic/plasmonic nanoparticles possess properties originating from each individual material. Such properties are beneficial for biological applications including bio-imaging, targeted drug delivery, in vivo diagnosis and therapy. Limitations regarding their stability and toxicity, however, challenge their safe use. Here, the one-step flame synthesis of composite SiO₂-coated Ag/Fe₂O₃ nanoparticles is demonstrated. The hermetic SiO₂ coating does not influence the morphology, the superparamagnetic properties of the iron oxide particles and the plasmonic optical properties of the silver particles. It does prevent, however, the release of toxic Ag⁺ ions from the nanosilver surface and reduces the interaction field among the iron oxide particles, resulting in a stable over 2 days suspensions with no signs of agglomeration (flocculation) and sedimentation. Therefore, the hybrid SiO₂-coated Ag/Fe₂O₃ nanoparticles do not exhibit the limiting physical properties of each individual component, while retain all the desired ones, facilitating their safe employment in such bio-applications.