A surface modification strategy on silicon nitride for developing biosensors

Jinpian Diao, Dacheng Ren, James R. Engstrom, Kelvin H. Lee

Research output: Contribution to journalArticlepeer-review

82 Scopus citations


A surface modification strategy for the use of giant magnetoresistive materials in the detection of protein-protein interactions is developed. This modification strategy is based on silanization of semiconductive materials. A native silicon nitride surface was treated with concentrated hydrofluoric acid to improve surface homogeneity. Nano-strip was used to oxidize silicon nitride to form a hydrophilic layer. Aminopropyltriethoxysilane was subsequently used to functionalize the treated surfaces to form amine groups, which were further activated with glutaraldehyde to introduce a layer of aldehyde groups. The effectiveness of this modification strategy was validated by chemiluminescence immunoassays of purified 6× His-HrpW of Pseudomonas syringae pv. tomato DC3000 and human transferrin. Signals with intensities related to concentrations of these two immobilized model proteins were observed. The modified surface was also validated by a more complex system: intercellular proteins secreted by DC3000. HrpW in these protein mixtures was successfully recognized by anti-HrpW antibodies when mixed proteins were immobilized onto activated surfaces. This surface modification strategy provides a platform onto which proteins can be directly immobilized for biosensor and protein array applications.

Original languageEnglish (US)
Pages (from-to)322-328
Number of pages7
JournalAnalytical Biochemistry
Issue number2
StatePublished - Aug 15 2005
Externally publishedYes


  • Biosensor
  • GMR
  • Immunoassays
  • Protein immobilization
  • Silicon nitride

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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