Li Ting, Cheryl Koh Jie Yan, Moudgil Akshay, Cao Huan, Wu Xihu, Chen Shuai, Hou Kunqi, Surendran Abhijith, Stephen Meera, Tang Cindy, Wang Chongwu, Wang Qi Jie, Tay Chor Yong, Leong Wei Lin
School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
ACS Nano. 2022 Aug 23;16(8):12049-12060. doi: 10.1021/acsnano.2c02191. Epub 2022 Aug 8.
Organic electrochemical transistors (OECTs) have recently attracted attention due to their high transconductance and low operating voltage, which makes them ideal for a wide range of biosensing applications. Poly-3,4-ethylenedioxythiophene:poly-4-styrenesulfonate (PEDOT:PSS) is a typical material used as the active channel layer in OECTs. Pristine PEDOT:PSS has poor electrical conductivity, and additives are typically introduced to improve its conductivity and OECT performance. However, these additives are mostly either toxic or not proven to be biocompatible. Herein, a biocompatible ionic liquid [MTEOA][MeOSO] is demonstrated to be an effective additive to enhance the performance of PEDOT:PSS-based OECTs. The influence of [MTEOA][MeOSO] on the conductivity, morphology, and redox process of PEDOT:PSS is investigated. The PEDOT:PSS/[MTEOA][MeOSO]-based OECT exhibits high transconductance (22.3 ± 4.5 mS μm), high μC* (the product of mobility μ and volumetric capacitance C*) (283.80 ± 29.66 F cm V s), fast response time (∼40.57 μs), and excellent switching cyclical stability. Next, the integration of sodium (Na) and potassium (K) ion-selective membranes with the OECTs is demonstrated, enabling selective ion detection in the physiological range. In addition, flexible OECTs are designed for electrocardiography (ECG) signal acquisition. These OECTs have shown robust performance against physical deformation and successfully recorded high-quality ECG signals.
有机电化学晶体管（OECTs）因其高跨导和低工作电压，近来备受关注，这使其成为广泛生物传感应用的理想选择。聚3,4 - 乙撑二氧噻吩：聚4 - 苯乙烯磺酸盐（PEDOT:PSS）是用作OECTs有源沟道层的典型材料。纯净的PEDOT:PSS导电性较差，通常引入添加剂以提高其导电性和OECT性能。然而，这些添加剂大多要么有毒，要么未被证明具有生物相容性。在此，一种生物相容性离子液体[MTEOA][MeOSO]被证明是增强基于PEDOT:PSS的OECTs性能的有效添加剂。研究了[MTEOA][MeOSO]对PEDOT:PSS的导电性、形态和氧化还原过程的影响。基于PEDOT:PSS/[MTEOA][MeOSO]的OECT表现出高跨导（22.3±4.5 mS/μm）、高μC*（迁移率μ与体积电容C*的乘积）（283.80±29.66 F/cm²V/s）、快速响应时间（约40.57 μs）以及出色的开关循环稳定性。接下来，展示了钠（Na）和钾（K）离子选择性膜与OECTs的集成，实现了生理范围内的选择性离子检测。此外，设计了用于心电图（ECG）信号采集的柔性OECTs。这些OECTs在面对物理变形时表现出强大的性能，并成功记录了高质量的ECG信号。
