Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (6): 1223-1229.doi: 10.3866/PKU.WHXB201702282

• ARTICLE • Previous Articles     Next Articles

Theoretical Analyses and Chemical Sensing Application of Surface Plasmon Resonance Effect of Nanoporous Gold Films

Li WANG1,2,Dan-Feng LU1,Ran GAO1,Jin CHENG1,Zhe ZHANG3,Zhi-Mei QI1,*()   

  1. 1 State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
    3 Beijing Jiaotong University, School of Computer and Information Technology, Beijing 100044, P. R. China
  • Received:2016-12-15 Published:2017-05-19
  • Contact: Zhi-Mei QI E-mail:zhimei-qi@mail.ie.ac.cn
  • Supported by:
    the National Key Basic Research Program of China (973)(2015CB352100);National Natural Science Foundation of China(61377064);National Natural Science Foundation of China(61401432);National Natural Science Foundation of China(61401019);National Natural Science Foundation of China(61675203);Research Equipment Development Project of Chinese Academy of Sciences(YZ201508)

Abstract:

Nanoporous gold films (NPGFs) are chemically robust and thermally stable, possessing large specific area and salient surface plasmon resonance (SPR) effect. With these features NPGFs are quite applicable for high-sensitivity SPR sensors. In this work, the SPR effect of NPGFs was theoretically analyzed and the dispersion relation of propagating surface plasmons at the NPGF/air interface was obtained. The optimal thickness of NPGF required for optimizing its SPR sensing performance was achieved to be about 60 nm. Large-area, uniform and ultrathin NPGFs were prepared by a two-step approach consisting of sputtering deposition and chemical dealloying. The SPR resonance band in the visible-near-infrared region and the sensing properties of NPGF were measured with the Kretschmann prism-coupling configuration. Porosity of the NPGF is determined to be about 0.38 by fitting the measured resonance wavelengths based on the combination of the Fresnel formula and the Bruggeman dielectric constant approximation theory. Since the non-modified NPGFs are hydrophilic and enable effective enrichment of bisphenol A (BPA) molecules in water, the NPGF-SPR sensor can easily detect BPA with concentrations as low as 5 nmol·L-1. After hydrophobilization of NPGFs, the sensor enables detection of trace benzo[a]pyrene (BaP) in water, with the detection limit of 1 nmol·L-1.

Key words: Nanoporous gold film, Propagating surface plasmon resonance, Enrichment, High sensitivity, Benzo[a]pyrene

MSC2000: 

  • O647