Ultrasensitive Coplanar Dual-Gate ISFETs for Point-of-Care Biomedical Applications
Ultrasensitive Coplanar Dual-Gate ISFETs for Point-of-Care Biomedical Applications
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DOI：
10.1021/acsomega.0c00427
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发表时间：
2020-06-09
期刊：
影响因子：
4.1
通讯作者：
Cho, Won-Ju
中科院分区：
文献类型：
--
作者：
Jeon, Jin-Hyeok;Cho, Won-Ju
传统的离子敏感场效应晶体管（ISFET）的灵敏度受到能斯特方程的限制，这不足以检测微弱的生物信号。在这项研究中，我们提出了一种基于绝缘体上硅共面双栅（Cop-DG）ISFET pH传感器，它表现出更好的性能比传统的ISFET pH传感器。Cop-DG ISFET采用由控制栅极（CG）和感测栅极（SG）组成的Cop-DG，其具有公共栅极氧化物和电隔离浮置栅极（FG）。由于CG和SG电容耦合到FG，这两个栅极可以有效地调制FET沟道的电导。所提出的传感器的优点是它能够有效地放大灵敏度根据FG和共面栅极（SG和CG）之间的电容耦合比，这是由SG和CG的面积确定。我们得到的pH灵敏度为304.12 mV/pH，这是显着大于传统的ISFET传感器（59.15 mV/pH，在25 ℃）。此外，我们还测量了迟滞和漂移效应，以确保传感器的稳定性和可靠性。由于其简单的结构，成本效益，以及良好的灵敏度和可靠性，我们相信，铜DG ISFET传感器提供了一个有前途的床旁生物医学应用。
The sensitivity of conventional ion-sensitive field-effect transistors (ISFETs) is limited by the Nernst equation, which is not sufficient for detecting weak biological signals. In this study, we propose a silicon-on-insulator-based coplanar dualgate (Cop-DG) ISFET pH sensor, which exhibits better performance than the conventional ISFET pH sensor. The Cop-DG ISFETs employ a Cop-DG consisting of a control gate (CG) and a sensing gate (SG) with a common gate oxide and an electrically isolated floating gate (FG). As CG and SG are capacitively coupled to FG, both these gates can efficiently modulate the conductance of the FET channel. The advantage of the proposed sensor is its ability to amplify the sensitivity effectively according to the capacitive coupling ratio between FG and coplanar gates (SG and CG), which is determined by the area of SG and CG. We obtained the pH sensitivity of 304.12 mV/pH, which is significantly larger than that of the conventional ISFET sensor (59.15 mV/pH, at 25 degrees C). In addition, we measured the hysteresis and drift effects to ensure the stability and reliability of the sensor. Owing to its simple structure, cost-effectiveness, and excellent sensitivity and reliability, we believe that the Cop-DG ISFET sensor provides a promising point-of-care biomedical applications.