Preparation and Applications of Fe-Core/ Au-ShellMagnetic Composite Nanoparticles

• Main Authors: Chao-Chin Lien, 連昭晴
• Other Authors: Dong-Hwang Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/r734sb

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 92 === 　　In this thesis, Fe@Au core-shell composite nanoparticles were prepared by microemulsion and thermal decomposition methods. The product was characterized and conjugated with the anti-cancer drug methotrexate (MTX). In the as synthesized product, the oxidation of iron nanoparticles could be hindered due to the surface coating of Au nanoshells. Also, via the conjugation with drugs or biomolecules, the product may become a nanocomposite with magnetic, optical, and biological or biomedical functions. Since the aims of labeling, targeting, and separation could be achieved simultaneously, the product may be used widely in biochemical and biomedical fields. 　　First, Fe@Au were prepared in the microemulsion system of water/CTAB/n-butanol/isooctane. By the analysis of XRD pattern, UV/VIS absorption spectra, and ESCA, the product was recognized to be the Fe@Au core-shell composite nanoparticles without the presence of iron oxide. Via surface modification, the product could be conjugated with MTX molecules. It was found that the fresh product has selective toxicity for cancer cells compared to the normal mucosal keratinocytes, while the product aged in air or aqueous solution for several days has significantly reduced toxicity . From the studies on the oxidation of the product and the releasing of ferrous ions, it was suggested that ferrous ions might release from the surface of iron core via the grain boundary of Au nanoshells. After aging in air or aqueous solution for several days, a thin layer of iron oxide might form on the surface of iron core within the grain boundary of Au nanoshells, which prevented from the further releasing of ferrous ions and oxidation of iron. Accordingly, in this study, an idea using the product as a smart drug was proposed. The fresh product could be used to kill the cancer cells selectively, while the product spontaneously transformed into nontoxic agents which significantly reduced potential accumulation of the toxic compounds and the systemic side effects. 　　Second, monodisperse Fe@Au core-shell composite nanoparticles were prepared by thermal decomposition of iron pentacarbonyl and reduction of gold acetate with 1,2-hexadecaneediol in the presence of stabilizers oleic acid and oleylamine. The analyses of XRD pattern and UV/VIS absorption spectrum revealed the formation of Fe@Au composite nanoparticles without the presence of iron oxide.