Surface-modified diamond field-effect transistors for enzyme-immobilized biosensors

Kwang Soup Song*, Munenori Degawa, Yusuke Nakamura, Hirofumi Kanazawa, Hitoshi Umezawa, Hiroshi Kawarada

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


The enzyme sensors using electrolyte-solution-gate diamond field effect transistors (SGFETs) have been developed for the first time. The hydrogen-terminated surface channel of the FETs was modified into partially aminated and oxygen-terminated (H-A-O-terminated) with irradiation of ultraviolet in an ammonia environment. The pH response of that is obtained about 50 mV/pH at pH 2-10. The concentration of substrates (urea or glucose) in the electrolyte solution has been detected by the pH change due to the bio-catalyzed effect of enzyme (urease or glucose oxidase), which is immobilized on the channel of SGFETs. The sensitivity of urea and glucose is approximately 30 mV/decade and 20 mV/decade respectively.

Original languageEnglish
Pages (from-to)L814-L817
JournalJapanese Journal of Applied Physics, Part 2: Letters
Issue number6 B
Publication statusPublished - 2004 Jun 15


  • Diamond SGFETs
  • Enzyme
  • Glucose
  • H-A-O-terminated
  • Urea

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


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