N. M. Abd-Alghafour, Naser M. Ahmed, and Z. Hassan
الملخص الانجليزي
Semiconductor oxide material-based pH sensors have been developed in numerous
sensing felds such as biosensors, environment sensing, chemical measurements,
and clinical investigations. However, the measurement of pH was considered as one
of the most important requirements in biotechnology, analytical chemistry, and
medicine applications. Bergveld fabricated the ion-sensitive feld-effect transistor
(ISFET) for pH sensor measurements in the 1970s (Bergveld 1970). Based on the
ion-sensitive feld-effect transistor, Yuqing et al. (2005) and Yin et al. (2000) developed a new structure of the pH measurements denoted as the extended gate feldeffect transistor, which offers numerous advantages such as simpler packaging, low
cost, and flexibility as compared to ion-sensitive feld-effect transistor (Chou et al.
2005; Chou et al. 2008). Numerous studies have been carried out using metal oxides
as pH-EGFET membranes. Guerra et al. (2009) fabricated V2O5 thin flm as pHEGFET sensor by using sol-gel technique. They explored the interaction between
the membranes with the solution charges and calculated the sensor sensitivity.