Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (8): 847-850.DOI: 10.6023/A15040262 Previous Articles     Next Articles



李振兴a,b, 赵爱武a,b, 高倩b, 郭红燕b, 王大朋b, 李磊a,b   

  1. a 中国科学技术大学化学系 合肥 230026;
    b 中国科学院合肥智能机械研究所 合肥 230031
  • 投稿日期:2015-04-15 发布日期:2015-06-02
  • 通讯作者: 赵爱武
  • 基金资助:

    项目受国家自然科学基金(Nos. 61378038, 21301179)、合肥物质科学技术中心方向项目培育基金(No. 2014FXZY003)和传感技术联合国家重点实验室的资助.

Fabrication of Superparamagnetic Fe3O4/Au@Ag and Its SERS Performance

Li Zhenxinga,b, Zhao Aiwua,b, Gao Qianb, Guo Hongyanb, Wang Dapengb, Li Leia,b   

  1. a Department of Chemistry, University of Science and Technology of China, Hefei 230026;
    b Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031
  • Received:2015-04-15 Published:2015-06-02
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 61378038, 21301179), the Direction program of Hefei Center of Physical Science and Technology (No. 2014FXZY003) and the State Key Laboratories of Transducer Technology.

In this paper, Fe3O4 nanoparticles were synthesized by solvothermal method and uniform silver-coated gold nanoparticles (Au@Ag NPs) were synthesized via seed growth through consecutive two-step reactions. Subsequently, Au@Ag NPs were assembled on the surface of Fe3O4 NPs functionalized with PEI due to the bond between -NH2 and Ag. We have regulated the SERS behavior of Fe3O4/Au@Ag NPs by adjusting the addition amount of Au@Ag. This Au@Ag NPs were characterized by Ultraviolet-visible (UV-vis) extinction spectroscopy. From the measurement of UV-vis spectra we can see that Au@Ag has a wide range of plasmon resonance from ca. 320 to 560 nm while one significant peak were observed at 530 nm for the Au NPs. This Fe3O4/Au@Ag NPs were systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and surface enhanced Raman spectroscopy (SERS). The SEM and TEM observation showed the NPs are highly monodispersive. The magnetic hysteresis loops showed the saturation magnetization (Ms) values of Fe3O4 NPs and Fe3O4/Au@Ag NPs are about 83.6 emu·g-1 and 57.1 emu·g-1, respectively. p-Aminothiophenol (p-ATP) molecules were employed to explore surface-enhanced Raman Spectroscopy (SERS) performance of Fe3O4/Au@Ag and showed excellent sensitivity to 2×10-9 mol/L. Simultaneously, Fe3O4@Au@Ag NPs were applied to the detection of thiram and showed sensitivity to 10-6 mol/L. Using these nanoprobes, analyte molecules can be easily captured, magnetically concentrated, and analyzed by SERS. In addition, the Fe3O4/Au@Ag NPs can be recycled with magnet, which exhibited great practical potentials.

Key words: superparamagnetism, nanocomposite, SERS, p-ATP, thiram