Author(s)

Juan Mendez-Garza, Biran Wang, Alexandra Madeira, Christophe Di Giorgio, Georges Bossis

Institut de Chimie de Nice, UMR 7272, Université de Nice-Sophia Antipolis, CNRS, Parc Valrose, Nice, France.
Laboratoire de Physique de la Matière Condensée, UMR 7336, Université de Nice-Sophia Antipolis, CNRS, Parc Valrose, Nice, France.

In this paper, we describe the synthesis of gold coated spindle-type iron nanoparticles and its surface modification by a thiolated fluorescently-labelled polyethylene glycol (PEG) polymer. A forced hydrolysis of ferric salts in the presence of phosphate ions was used to produce α-Fe₂O₃ spindle-type particles. The oxide powders were first reduced to α-iron under high temperature and controlled dihydrogen atmosphere. Then, the resulting magnetic spindle-type particles were covered by a shell of gold. The formation of the core@shell structure was driven by a redox-transmetalation reaction between iron(0) at the surface of particles and a gold(III) salt. Protected against oxidation, the Fe@Au core@shell nanoparticles were then grafted with a water soluble fluorescent-PEG-thiol. TEM, XRD, EDX and measurements of magnetic properties of particles confirm 1) the conversion of hematite into iron and 2) their subsequent surface protection with a gold shell. Furthermore, the functionalization of the gold nanoparticle surface with a PEG carrying a fluorescent dye was unambiguously attested by confocal laser scanning microscopy.

Core@shell; Spindle-Type; Hematite; Magnetic Particles; Gold Coating; Fluorescent-PEG

J. Mendez-Garza, B. Wang, A. Madeira, C. Giorgio and G. Bossis, "Synthesis and Surface Modification of Spindle-Type Magnetic Nanoparticles: Gold Coating and PEG Functionalization," Journal of Biomaterials and Nanobiotechnology, Vol. 4 No. 3, 2013, pp. 222-228. doi: 10.4236/jbnb.2013.43027.