Detection of protein-protein interactions on SiO2/Si surfaces by spectroscopic ellipsometry

Seigo Kodera, Toshihide Okajima, Hidehiko Iwabuki, Daisuke Kitaguchi, Shun'ichi Kuroda, Tatsuo Yoshinobu, Katsuyuki Tanizawa, Masamitsu Futai, Hiroshi Iwasaki

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


We have applied spectroscopic ellipsometry to sensitive detection of specific protein-protein interactions on SiO2/Si substrates. First, the change of ellipticity of the reflected polarized light (600-1100nm) was correlated with the thickness of the protein layer immobilized on SiO 2/Si surfaces by measuring monomeric (myoglobin) and homotetrameric (hemoglobin) proteins with a similar monomer size. Protein-protein interactions were then measured with the antigen/antibody and cell-surface receptor/ligand systems; in each system either of the two proteins was bound to SiO 2/Si substrates. Consequently, significant ellipticity changes were observed only for the cases where the interactions were specific. A specific antibody binding was also detectable with an antigen displayed on the surface of bacteriophage particles. These results show the usefulness of spectroscopic ellipsometry for sensitive detection of protein-protein interactions and its applicability to a detection method for the protein-based biochips to be developed in the future.

Original languageEnglish
Pages (from-to)65-70
Number of pages6
JournalAnalytical Biochemistry
Issue number1
Publication statusPublished - 2003 Oct 1


  • Biochips
  • Protein-protein interaction
  • Sensitive detection
  • Spectroscopic ellipsometry


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