Optical Characteristics of Bimetallic Silver-Gold Film Structure in Surface Plasmon Resonance Sensor Applications

표면 플라즈몬 공명 센서에서의 쌍금속 은-금 박막 구조의 광학 특성

  • Published : 2007.01.01

Abstract

Surface plasmon resonance(SPR) has been widely studied for biological and chemical sensing applications. The present study conducts numerical simulation for the single and bimetallic layer SPR configurations by using the multiple beam interference matrix(MBIM) method to investigate the influence of wave interference and complex refractive indices of materials on optical characteristics such as reflectance and optical phase shift which are used for sensing. First, calculated reflectances are compared with experimental data for validation. In addition, in the single film structures this study finds out the appropriate film thicknesses with minimum reflectance for cases of gold film and silver film. For a bimetallic silver-gold film structure, in particular, the bimetallic film thicknesses that has the minimum reflectance are found 36 nm for silver and 5 nm for gold. From the results, the use of phase shift would be useful compared to reflectance in determining the SPR configuration because the phase shift becomes more sensitive than reflectance.

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References

  1. Jiri Homola, et al., 'Surface Plasmon Resonance Sensors: Review', Sensors and Actuators B, vol. 54 No. 1/2 3-15, 1999
  2. Ong, B. H., et al., 'Optimised Film Thickness for Maximum Evanescent Field Enhancement of a Bimetallic Film Surface Plasmon Resonance Biosensor', Sensors and Actuators B, vol. 114, No 2, pp. 1028-1034, 2006 https://doi.org/10.1016/j.snb.2005.07.064
  3. Jiri Homola, 'Present and Future of Surface Plasmon Resonance Biosensors', Analytical and Bioanalytical Chemistry, vol. 377, No.3, 528-539, 2003 https://doi.org/10.1007/s00216-003-2101-0
  4. Marvin J. Weber, Handbook of Optical Materials, CRC, pp. 55-69, Press, 2003
  5. Vitalii Silin, et al., 'SPR Studies of the Nonspecific Adsorption Kinetics of Human IgG and BSA on Gold Surfaces Modified by Self- Assembled Monolayers (SAMs)', Journal of Colloid and Interface Science, vol. 185, No.1, pp. 94-103 , 1997 https://doi.org/10.1006/jcis.1996.4586
  6. Shuai Shen, et al., 'Optical Phase-Shift Detection of Surface Plasmon Resonance', Applied Optics, vol. 37, No 10, pp. 1747-1751, 1998 https://doi.org/10.1364/AO.37.001747