Real-time optical biosensor based on differential phase measurement of surface plasmon resonance

H. P. Ho, Wing Cheung Law, S. Y. Wu, Chinlon Lin, S. K. Kong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

40 Citations (Scopus)


We report a real-time differential phase measurement technique which can be implemented in optical surface plasmon resonance biosensors. The important feature of our design is that sensitivity has been greatly improved by measuring the differential phase change between the s and p-polarizations. Real-time measurement capability is achieved by using a phase extracting routine which continuously monitors the waveforms captured by two photo-detectors. Measurement capability of our setup is demonstrated through real-time monitoring of bovine serum albumin (BSA)/anti-BSA binding reaction. The estimated sensitivity of our current setup is 7.4 ng/ml.
Original languageEnglish
Pages (from-to)2177-2180
Number of pages4
JournalBiosensors and Bioelectronics
Issue number10 SPEC. ISS.
Publication statusPublished - 15 Apr 2005
Externally publishedYes


  • Optical phase
  • Surface plasmon resonance

ASJC Scopus subject areas

  • Biotechnology
  • Analytical Chemistry
  • Electrochemistry

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