Wide dynamic range phase-sensitive surface plasmon resonance biosensor based on measuring the modulation harmonics

Wing Cheung Law, Przemyslaw Markowicz, Ken Tye Yong, Indrajit Roy, Alexander Baev, Sergiy Patskovsky, Andrei V. Kabashin, Ho Pui Ho, Paras N. Prasad

Research output: Journal article publicationJournal articleAcademic researchpeer-review

47 Citations (Scopus)


In this study, a novel phase-sensitive surface plasmon resonance (SPR) setup, based on temporal modulation of a pumping beam by a photoelastic modulator, and subsequent extraction of phase information at the second and the third harmonics of the modulation frequency, has been developed to study biomolecular interactions on SPR-supporting gold. We demonstrated that the design setup provides ultra-high phase sensitivity, together with a wide dynamic range of measurements. In particular, the proposed scheme was used to study real-time interaction of biotin-protein and streptavidin-BSA complexes. We have found that the proposed technique has a detection limit as high as 2.89 × 10-7in terms of refractive index units (RIU). In terms of biosensing performance, a detection sensitivity of 1.3 nM from the streptavidin-maleimide/thiolated BSA complex binding reaction has also been demonstrated.
Original languageEnglish
Pages (from-to)627-632
Number of pages6
JournalBiosensors and Bioelectronics
Issue number5
Publication statusPublished - 15 Dec 2007
Externally publishedYes


  • Biosensor
  • Photoelastic modulator
  • Surface plasmon resonance

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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