Synthesis and Surface Modification of Spindle-Type Magnetic Nanoparticles: Gold Coating and PEG Functionalization

• 作者: Alexandra Madeira Biran Wang Christophe Di Giorgio Georges Bossis Juan Mendez-Garza
• 来源期刊: 生物材料与纳米技术(英文)
• 学科: 医学
• 关键词: Core@shell Spindle-Type HEMATITE Magnetic Particles GOLD COATING Fluorescent-PEG
• 年，卷（期）: 2013,（3）
• 页码范围: 222-228
• 页数: 7页
• 分类号: R73

摘要

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.