高等学校化学学报 ›› 2014, Vol. 35 ›› Issue (10): 2207-2213.doi: 10.7503/cjcu20140297

• 物理化学 • 上一篇    下一篇

基于Kretschmann结构的金银合金薄膜的SERS效应

刘德龙, 赵乔, 逯丹凤, 祁志美()   

  1. 中国科学院电子学研究所传感技术国家重点实验室, 北京 100190
  • 收稿日期:2014-04-02 出版日期:2014-10-10 发布日期:2014-09-30
  • 作者简介:联系人简介: 祁志美, 男, 博士, 研究员, 主要从事集成光学传感器技术和表/界面光谱表征方法研究. E-mail: zhimei-qi@mail.ie.ac.cn
  • 基金资助:
    国家重大科学仪器设备开发项目(批准号: 2011YQ0301240802)、 国家自然科学基金(批准号: 61377064)和北京市自然科学基金(批准号: 3131001)资助

Surface Enhanced Raman Scattering Effect of Au-Ag Alloy Films Based on Kretschmann Configuration

LIU Delong, ZHAO Qiao, LU Danfeng, QI Zhimei*()   

  1. State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2014-04-02 Online:2014-10-10 Published:2014-09-30
  • Contact: QI Zhimei E-mail:zhimei-qi@mail.ie.ac.cn
  • Supported by:
    Supported by the Major National Scientific Instrument and Equipment Development Project of China(No.2011YQ0301240802), the Natio-nal Natural Science Foundation of China(No.61377064) and the Beijing Natural Science Foundation, China(No.3131001)

摘要:

利用 Kretschmann棱镜耦合结构和532 nm激光光源, 测试了金银合金薄膜的表面增强拉曼散射(SERS)效应, 并与纯金薄膜的测试结果进行了比较. 结果显示, 在激发光为p偏振态且入射角近似等于表面等离子体共振(SPR)角时, 附着于金银合金薄膜表面的Nile Blue分子的 SERS信号达到最强, 比利用纯金薄膜测得的SERS信号高约2倍. 实验结果还表明, 在金银合金薄膜表面自组装金纳米粒子后, Nile Blue吸附层的SERS信号比自组装纳米金之前测得的信号增强了至少3倍, 比利用纳米金修饰的纯金薄膜测得的信号高出2倍多. 在棱镜底面沿薄膜法线收集的SERS信号是完全非偏振光, 而从棱镜侧面收集的SERS信号是p偏振光, 是拉曼光借助SPR效应产生的定向发射.

关键词: 金银合金薄膜, 表面增强拉曼散射, Kretschmann结构, 偏振状态

Abstract:

The surface enhanced Raman scattering(SERS) effect of Au-Ag alloy films was investigated, using a 532 nm laser source and the Kretschmann configuration. The experimental results indicate that when the incidence angle of the p-polarized beam meets the surface plasmon resonance(SPR) condition, the intensities of Raman peaks for Nile Blue molecules immobilized on the Au-Ag alloy film reaches maxima, being almost 2 times as high as those achieved with the pure gold layer. Gold nanoparticles(GNP) modification of the Au-Ag alloy films resulted in more than 3 times increase in Raman peak intensity. With the GNP-modified Au-Ag alloy film the Raman peaks are 2 times higher than those with the GNP-modified pure gold layer. The Raman signals detected with the probe placed below the prism substrate are completely non-polarized, but those detected along the reflected light beam on the side of the prism are p-polarized due to the SPR-coupled directional emission of Raman light excited in the evanescent-field region. The work demonstrated that the Au-Ag alloy films are advantageous over the conventional gold films for surface plasmon enhanced Raman spectroscopy.

Key words: Au-Ag alloy film, Surface enhanced Raman scattering(SERS), Kretschmann configuration, Polarized state

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