Kamarozaman Nur Syahirah, Zainal Nurbaya, Rosli Aimi Bazilah, Zulkefle Muhammad Alhadi, Nik Him Nik Raikhan, Abdullah Wan Fazlida Hanim, Herman Sukreen Hana, Zulkifli Zurita
Integrated Sensors Research Group, School of Electrical Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Shah Alam 40450, Selangor, Malaysia.
NANO-ElecTronic Centre, School of Electrical Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Shah Alam 40450, Selangor, Malaysia.
Gels. 2022 Oct 26;8(11):690. doi: 10.3390/gels8110690.
A highly selective and sensitive EGFET-pH sensor based on composite TiO-PANI had been developed in this work. A sol-gel titanium dioxide (TiO) and the composite of TiO with semiconducting polyaniline (PANI) were deposited using a simple spin-coating method on an indium tin oxide (ITO) substrate. The films have been explored as a sensing electrode (SE) of extended gate field-effect transistor (EGFET) for pH applications in the range of pH 2 to 12. The pH sensitivities between TiO, TiO-PANI bilayer composite, and TiO-PANI composite thin films were discussed. Among these, the TiO-PANI composite thin film showed a super-Nernstian behavior with high sensitivity of 66.1 mV/pH and linearity of 0.9931; good repeatability with a standard deviation of 0.49%; a low hysteresis value of 3 mV; and drift rates of 4.96, 5.54, and 3.32 mV/h in pH 4, 7, and 10, respectively, for 6 h. Upon applying the TiO-PANI composite as the SE for nitrate measurement, low sensitivity of 12.9 mV/dec was obtained, indicating that this film is a highly selective sensing electrode as a pH sensor. The surface morphology and crystallinity of the thin films were also discussed.
在本工作中，已开发出一种基于TiO-PANI复合材料的高选择性和高灵敏度的场效应晶体管型pH传感器。采用简单的旋涂法将溶胶-凝胶二氧化钛（TiO₂）以及TiO₂与半导体聚苯胺（PANI）的复合材料沉积在氧化铟锡（ITO）衬底上。已将这些薄膜用作扩展栅场效应晶体管（EGFET）的传感电极（SE），用于pH值在2至12范围内的pH应用。讨论了TiO₂、TiO₂-PANI双层复合材料和TiO₂-PANI复合薄膜之间的pH灵敏度。其中，TiO₂-PANI复合薄膜表现出超能斯特行为，灵敏度高达66.1 mV/pH，线性度为0.9931；具有良好的重复性，标准偏差为0.49%；滞后值低至3 mV；在pH值为4、7和10时，6小时内的漂移率分别为4.96、5.54和3.32 mV/h。将TiO₂-PANI复合材料用作硝酸盐测量的传感电极时，灵敏度低至12.9 mV/dec，这表明该薄膜作为pH传感器是一种高选择性传感电极。还讨论了薄膜的表面形貌和结晶度。
