Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (04): 867-873.doi: 10.3866/PKU.WHXB201302222

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Surface Plasmon Resonance Sensing Properties of Nanoporous Gold Thin Films

ZHANG Zhe, LU Dan-Feng, QI Zhi-Mei   

  1. State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2013-01-15 Revised:2013-02-20 Published:2013-03-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (60978042), National Key Basic Research Program of China (973) (2009CB320300), and Beijing Natural Science Foundation, China (3131001).

Abstract:

Nanoporous gold films were prepared by immersing Au-Ag alloy films with a thickness of ca 60 nm sputtered on glass substrates in nitrate acid to remove the Ag component. Using a home-made wavelength-interrogated surface plasmon resonance (SPR) sensor platform, the influence of the immersion time on the SPR properties of the nanoporous gold film was investigated. If the nanoporous gold film was immersed in aqueous solution, SPR was not detected in the wavelength range from 400 to 900 nm. However, when the nanoporous gold films were exposed to air, a strong SPR absorption peak was detected in the same spectral range. The peak position gradually moved to longer wavelength as the immersion time extended. The SPR of the nanoporous gold film in air enables the film to be used for in situ monitoring of gas-phase molecular adsorption and ex situ detection of biochemical molecules adsorbed in the liquid phase. Ex situ detection of three kinds of small molecules (L-glutathione, L-cysteine, and cysteamine) adsorbed to the nanoporous gold film was fulfilled. The results were compared with those obtained using a conventional SPR chip with a dense gold film, revealing that the nanoporous gold films have a higher sensitivity and lower detection limit than the dense gold layer because of their larger surface area. Adsorption of ethanol molecules in the gas phase was monitored in situ, and the time required to reach adsorption equilibrium was about 160 min.

Key words: Sputtered Au-Ag alloy film, Nanoporous gold film, Surface plasmon resonance, Resonance wavelength, Small molecule, High sensitivity

MSC2000: 

  • O647