Sensors (Jun 2016)

High Sensitivity pH Sensor Based on Porous Silicon (PSi) Extended Gate Field-Effect Transistor

  • Naif H. Al-Hardan,
  • Muhammad Azmi Abdul Hamid,
  • Naser M. Ahmed,
  • Azman Jalar,
  • Roslinda Shamsudin,
  • Norinsan Kamil Othman,
  • Lim Kar Keng,
  • Weesiong Chiu,
  • Hamzah N. Al-Rawi

DOI
https://doi.org/10.3390/s16060839
Journal volume & issue
Vol. 16, no. 6
p. 839

Abstract

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In this study, porous silicon (PSi) was prepared and tested as an extended gate field-effect transistor (EGFET) for pH sensing. The prepared PSi has pore sizes in the range of 500 to 750 nm with a depth of approximately 42 µm. The results of testing PSi for hydrogen ion sensing in different pH buffer solutions reveal that the PSi has a sensitivity value of 66 mV/pH that is considered a super Nernstian value. The sensor considers stability to be in the pH range of 2 to 12. The hysteresis values of the prepared PSi sensor were approximately 8.2 and 10.5 mV in the low and high pH loop, respectively. The result of this study reveals a promising application of PSi in the field for detecting hydrogen ions in different solutions.

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