Bioelectronic devices must be fast and sensitive to interact with the rapid, low-amplitude signals generated by neural tissue. They should also be biocompatible and soft, and should exhibit long-term stability in physiologic environments. Here, we develop an enhancement-mode, internal ion-gated organic electrochemical transistor (e-IGT) based on a reversible redox reaction and hydrated ion reservoirs within the conducting polymer channel, which enable long-term stable operation and shortened ion transit time. E-IGT transient responses depend on hole rather than ion mobility, and combine with high transconductance to result in a gain–bandwidth product that is several orders of magnitude above that of other ion-based transistors. We used these transistors to acquire a wide range of electrophysiological signals, including in vivo recording of neural action potentials, and to create soft, biocompatible, long-term implantable neural processing units for the real-time detection of epileptic discharges. E-IGTs offer a safe, reliable and high-performance building block for chronically implanted bioelectronics, with a spatiotemporal resolution at the scale of individual neurons.

生物电子设备必须快速且敏感，才能与神经组织产生的快速，低振幅信号相互作用。它们还应具有生物相容性和柔软性，并应在生理环境中表现出长期稳定性。在这里，我们基于可逆氧化还原反应和导电聚合物通道内的水合离子库，开发了一种增强模式的内部离子门控有机电化学晶体管（e-IGT），可实现长期稳定运行并缩短离子传输时间。E-IGT瞬态响应取决于空穴而不是离子迁移率，并与高跨导相结合，导致增益带宽乘积比其他基于离子​​的晶体管高出几个数量级。我们使用这些晶体管来获取各种电生理信号，包括体内记录神经动作电位，并创建软的，生物相容的，长期可植入的神经处理单元，用于实时检测癫痫放电。E-IGT为长期植入的生物电子学提供了安全，可靠和高性能的构建块，其时空分辨率达到了单个神经元的规模。