(747c) Hybrid, Silica-Coated, Janus-Like Plasmonic-Magnetic Nanoparticles

Sotiriou, G. A. - Presenter, Particle Technology Laboratory, ETH Zurich
Teleki, A. - Presenter, Particle Technology Laboratory, ETH Zurich
Pratsinis, S. E. - Presenter, Swiss Federal Institute of Technology, Particle Technology Laboratory, ETH Zurich

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 [1]. Here, the one-step flame synthesis of composite SiO2-coated Ag/Fe2O3 nanoparticles is demonstrated. The hermetic SiO2 coating [2] 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 [3] and reduces the interaction field among the iron oxide particles, resulting in a stable suspensions with no signs of agglomeration (flocculation) and sedimentation [4]. The feasibility of these multi-component nanoparticles with superior properties and performance is explored by their specific binding with live tagged cells, and the detection as well as magnetic manipulation of the latter is demonstrated. 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.

[1] Sotiriou, G. A. & Pratsinis, S. E. Antibacterial activity of nanosilver ions and particles. Environ. Sci. Technol. 44, 5649-5654 (2010).

[2] Sotiriou, G. A., Sannomiya, T., Teleki, A., Krumeich, F., Vörös, J. & Pratsinis, S. E. Non-Toxic Dry-Coated Nanosilver for Plasmonic Biosensors. Adv. Funct. Mater. 20, 4250-4257 (2010).

[3] Sotiriou, G. A., Teleki, A., Camenzind, A., Krumeich, F., Meyer, A., Panke, S. & Pratsinis, S. E. Nanosilver on nanostructured silica: Antibacterial activity and Ag surface area. Chem. Eng. J. in press, DOI: 10.1016/j.cej.2011.1001.1099 (2011).

[4] Sotiriou, G. A., Hirt, A. M., Lozach, P. Y., Teleki, A., Krumeich, F. & Pratsinis, S. E. Hybrid, Silica-Coated, Janus-like Plasmonic-Magnetic Nanoparticles. Chem. Mater. 23, 1985-1992 (2011).