Department of Electronic Engineering, Kwangwoon University, Seoul 01897, Republic of Korea.
Department of Electrical Engineering, Kwangwoon University, Seoul 01897, Republic of Korea.
J Nanosci Nanotechnol. 2019 Oct 1;19(10):6682-6686. doi: 10.1166/jnn.2019.17093.
A simple and stable pH sensor based on an extended-gate field-effect transistor (EGFET) is demonstrated using electron-beam deposited Al₂O₃ as a pH sensing layer. The threshold voltage of the EGFET is modulated by different pH values of the buffer solution. A control experiment with a bare Au electrode confirms that the stable pH sensing response with linearity and reproducibility originates from the Al2O3 sensing layer. The minimum area of the pH sensing layer is estimated by considering that the different sizes of the sensing layer are easily modeled with different values of external capacitors connected to the readout transistor. The study verifies that the pH detection accuracy is improved by using the reference electrode with a KCl electrolyte.
本文展示了一种基于扩展栅场效应晶体管（EGFET）的简单稳定的 pH 传感器，该传感器使用电子束沉积的 Al₂O₃ 作为 pH 传感层。EGFET 的阈值电压通过缓冲溶液的不同 pH 值进行调制。使用裸 Au 电极进行的对照实验证实，具有线性和可重复性的稳定 pH 传感响应源自 Al2O3 传感层。通过考虑到与读出晶体管相连的外部电容器的不同值可以容易地对不同尺寸的传感层进行建模，从而估算出 pH 传感层的最小面积。该研究验证了使用具有 KCl 电解质的参比电极可以提高 pH 检测精度。
