Organic electrochemical transistors (OECTs) have shown promise as transducers and amplifiers of minute electronic potentials due to their large transconductances. Tuning the OECT threshold voltage is important to achieve low‐powered devices with amplification properties within the desired operational voltage range. However, traditional design approaches have struggled to decouple channel and materials properties from threshold voltage, thereby compromising on several other OECT performance metrics, such as electrochemical stability, transconductance, and dynamic range. In this work, simple solution‐processing methods are utilized to chemically dope polymer gate electrodes, thereby controlling their work function, which in turn tunes the operation voltage range of the OECTs without perturbing their channel properties. Chemical doping of initially air‐sensitive polymer electrodes further improves their electrochemical stability in ambient conditions. Thus, OECTs that are simultaneously low‐powered and electrochemically resistant to oxidative side reactions under ambient conditions are demonstrated. This approach shows that threshold voltage, which is once interwoven with other OECT properties, can in fact be an independent design parameter, expanding the design space of OECTs.

The development of sensor electrode materials for the detection of metabolites will enable point‐of‐care diagnostic devices for the monitoring and treatment of metabolic diseases such as diabetes. Current state‐of‐the‐art glucose sensing electrodes employ the organic salt tetrathiafulvene tetracyanoquinodimethane (TTF TCNQ) to receive electrons directly from enzymatic reactions of glucose. However, TTF TCNQ is insoluble in most solvents, making it challenging to deposit high‐quality electrodes. Furthermore, its hydrophobicity hinders its interface with aqueous solutions in physiological environments. To overcome these issues, TCNQ derivatives are introduced into an electron‐rich and hydrophilic conjugated polymer. Thus, a polymeric electrode is demonstrated that is easily solution processible and can undergo volumetric direct electron transfer with glucose reactions throughout its bulk. This study further elucidates the electron transfer mechanism during chemical doping and metabolite sensing reactions to inform general design rules for this new class of glucose sensing materials.