Operation mechanism of organic electrochemical transistors as redox chemical transducers
Operation mechanism of organic electrochemical transistors as redox chemical transducers
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有机电化学晶体管作为氧化还原化学传感器的工作机制
DOI：
10.1039/d1tc02224e
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发表时间：
2021
影响因子：
6.4
通讯作者：
Salleo, Alberto
中科院分区：
文献类型：
--
作者：
Tan, Siew Ting;Keene, Scott;Giovannitti, Alexander;Melianas, Armantas;Moser, Maximilian;McCulloch, Iain;Salleo, Alberto
通过与氧化还原活性分析物的反应来控制有机混合离子电子导体（OMIECs）的电荷密度的能力使得能够作为电化学氧化还原传感器应用。它们的电荷密度依赖性电导率还可以通过从电极注入电荷来调节，例如在有机电化学晶体管（OECTs）中，其中OMIEC通道的体积充电能够实现低电位的优异放大和放大。最近的努力已经将化学检测与OECT的晶体管功能相结合，以实现紧凑的电化学传感器。然而，这些传感器通常达不到OECT的预期放大性能。在这里，我们调查各种OECT架构的操作机制，推导出实现可靠的化学检测和信号放大所需的设计原则。通过利用不可极化的栅电极并在与OECT分开的隔室中进行化学反应，最近开发的反应单元OECT实现了对OECT通道的电荷密度的可靠调制。这项工作表明，OECT化学传感器的系统和合理设计需要了解导致通道电位（电荷密度）变化的电化学过程，这是放大背后的潜在现象。
The ability to control the charge density of organic mixed ionic electronic conductors (OMIECs) via reactions with redox-active analytes has enabled applications as electrochemical redox sensors. Their charge density-dependent conductivity can additionally be tuned via charge injection from electrodes, for instance in organic electrochemical transistors (OECTs), where volumetric charging of the OMIEC channel enables excellent transconductance and amplification of low potentials. Recent efforts have combined the chemical detection with the transistor function of OECTs to achieve compact electrochemical sensors. However, these sensors often fall short of the expected amplification performance of OECTs. Here, we investigate the operation mechanism of various OECT architectures to deduce the design principles required to achieve reliable chemical detection and signal amplification. By utilizing a non-polarizable gate electrode and conducting the chemical reaction in a compartment separate from the OECT, the recently developed Reaction Cell OECT achieves reliable modulation of the OECT channel's charge density. This work demonstrates that systematic and rational design of OECT chemical sensors requires understanding the electrochemical processes that result in changes in the potential (charge density) of the channel, the underlying phenomenon behind amplification.