Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (1): 41-46.DOI: 10.6023/A14100734 Previous Articles     Next Articles



刘德龙a, 逯丹凤a, 赵乔a, 陈晨a, 祁志美a,b   

  1. a 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;
    b 国民核生化灾害防护国家重点实验室 北京 102205
  • 投稿日期:2014-10-23 发布日期:2014-12-15
  • 通讯作者: 逯丹凤
  • 基金资助:

    项目受国家重大科学仪器设备开发项目(No. 2011YQ0301240802)、国家自然科学基金(No. 61377064)、北京市自然科学基金(No. 3131001)和国民核生化灾害防护国家重点实验室开放基金(No. SKLNBC2014-11)资助.

Large-area High-performance SERS Substrates Prepared with a Combination of Mesoporous Silica Film and AuAg Alloy film

Liu Delonga, Lu Danfenga, Zhao Qiaoa, Chen Chena, Qi Zhimeia,b   

  1. a State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190;
    b State Key Laboratory of NBC Protection for Civilian, Beijing 102205
  • Received:2014-10-23 Published:2014-12-15
  • Supported by:

    Project supported by the Major National Scientific Instrument and Equipment Development Project of China (No. 2011YQ0301240802), the National Natural Science Foundation of China (No. 61377064), the Beijing Natural Science Foundation (No. 3131001) and the State Key Laboratory of NBC Protection for Civilian (No. SKLNBC2014-11).

Uniform large-area and high-performance surface enhanced Raman scattering (SERS) substrates were prepared for the first time by using a simple three-step method. The method contains sputtering deposition of an AuAg alloy layer on the glass sheet and subsequent dip-coating of a sol-gel copolymer-templated silica film on the alloy layer and finally thermal treatment of the double-layer coated glass sheet in air at 450 ℃ for several hours. The thermal treatment leads to formation of the mesoporous silica (MS) film. The scanning electron microscope images show that the top layer of MS has the open-pore structure that facilitates rapid diffusion of small molecules into the film. The energy dispersive X-ray (EDX) spectroscopy analyses indicate that the thermal treatment of the substrate results in the loss of Ag atoms in the AuAg alloy film accompanied with the nanostructure formation in the film. The systematic measurements of SERS spectra for Nile blue (NB) and Crystal violet (CV) demonstrate that the insertion of a 20-nm-thick gold layer between the glass sheet and a 50-nm-thick AuAg alloy film can effectively increase the SERS enhancement factor of the substrate. Dependence of the SERS signal on the substrate immersion time was investigated with an aqueous solution of 50 nmol·L-1 CV, and the findings indicate that the intensity of SERS signal increases with increasing the immersion time up to 30 min after which the signal becomes stable. The SERS signal intensity detected 15 min after immersion is 85% of its stable value. The position of each peak in the SERS spectrum for the adsorbed CV molecules is perfectly identical to that in the conventional Raman spectrum obtained with the aqueous CV solution, giving a sign that the MS film enables to prevent the metal from interfering the positions of SERS peaks. The experimental results demonstrate that such novel SERS substrates have the detection limit of 1 nmol·L-1 NB.

Key words: AuAg alloy film, mesoporous silica film, SERS substrate, large area, high performance, detection limit