Biomolecular sensors utilizing waveguide modes excited by evanescent fields

M. Fujimaki*, C. Rockstuhl, X. Wang, K. Awazu, J. Tominaga, T. Ikeda, Y. Koganezawa, Y. Ohki

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Properties of evanescent-field-coupled waveguide-mode sensors consisting of a multi-layer structure made of a SiO2 waveguide, a thin metal layer (Au, Cu, W or Ti), and a high refractive index glass substrate illuminated under the Kretschmann configuration have been theoretically and experimentally investigated. In all cases, reflectivity changes attributed to streptavidin combining to biotinyl groups were observed in close spectral vicinity of the waveguide resonances. The sensors with the Au and the Cu layers show superior sensitivity as compared to those with the W and the Ti layers, whereas the W and Ti layers show better thermal and chemical stability. The results indicate that the materials of thin metal layers should be chosen in accordance with the purpose of sensors and/or environment in which the sensors are used.

Original languageEnglish
Pages (from-to)320-326
Number of pages7
JournalJournal of Microscopy
Issue number2
Publication statusPublished - 2008 Feb


  • Evanescent field
  • Reflecting film
  • Sensor
  • Waveguide mode

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Histology


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