Ag-Coated Fe3O4@SiO2 Three-Ply Composite Microspheres: Synthesis, Characterization, and Application in Detecting Melamine with Their Surface-Enhanced Raman Scattering

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• 作者：Haibo Hu ; Zhenghua Wang ; Ling Pan ; Suping Zhao ; Shiyu Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：May 6, 2010
• 年：2010
• 卷：114
• 期：17
• 页码：7738-7742
• 全文大小：256K
• 年卷期：v.114,no.17(May 6, 2010)
• ISSN：1932-7455

文摘

Ag nanoparticles with average sizes of 20 nm were well-dispersed on the surfaces of Fe₃O₄@SiO₂ composite microspheres through a simple wet-chemical method employing the Ag-mirror reaction. The as-synthesized Ag-coated Fe₃O₄@SiO₂ three-ply composite microspheres are monodisperse and bifunctional, with ferromagnetic and surface-enhanced Raman scattering (SERS) properties. The products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDX). SERS signals of typical analytes such as rhodamine 6G (Rh 6G) were observed on Ag nanoparticles from the Ag-coated Fe₃O₄@SiO₂ microspheres, even though the concentration of the analyte was as low as 1 × 10⁻¹⁵ M (Rh 6G). The Ag-coated Fe₃O₄@SiO₂ microspheres were applied to detecting melamine, and strong SERS signals were obtained with melamine concentration of 1 × 10⁻⁶ M. This work may provide a potential and unique technique to detect melamine.