A urea biosensor based on pH-sensitive Sm2TiO5 electrolyte-insulator-semiconductor

Tung Ming Pan*, Ming De Huang, Wan Ying Lin, Min Hsien Wu

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

26 Scopus citations


A urea biosensor based on pH-sensitive Sm2TiO5 electrolyte-insulator-semiconductor (EIS) has been described. We used X-ray diffraction, Auger electron spectroscopy, and atomic force microscopy to investigate the structural and morphological features of high-k Sm2TiO5 sensing membranes that had been subjected to annealing at different temperatures. The EIS device incorporating a high-k Sm2TiO5 sensing film that had been annealed at 900°C exhibited good sensing characteristics, including a high sensitivity of 60.5mV/pH (in solutions from pH 2 to 12), a small hysteresis voltage of 2.72mV (in the pH loop 7→4→7→10→7), and a low drift rate of 1.15mVh-1 (in the buffer solution at pH 7). The Sm2TiO5 EIS device also showed a high selective response towards H+. This improvement can be attributed to the small number of crystal defects and the large surface roughness. In addition, the urea biosensor based on pH-sensitive EIS incorporating a Sm2TiO5 sensing membrane annealed at 900°C allowed the potentiometric analysis of urea, at concentrations ranging from 0.1 to 32mM, with a sensitivity of 72.85mV/purea.

Original languageEnglish
Pages (from-to)68-74
Number of pages7
JournalAnalytica Chimica Acta
Issue number1-2
StatePublished - 06 2010


  • Biosensor
  • Electrolyte-insulator-semiconductor
  • PH-sensitive
  • SmTiO
  • Urea


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