Ready-to-Use OECT Biosensor toward Rapid and Real-Time Protein Detection in Complex Biological Environments

作者：Shouyan Zhang, Chunyang Xia, Jun Wang, Shixiong Chen, Yixuan Wang, Shu‐Hua Zhang, Zhi Geng, Ke Tang, Arzum Erdem, Bo Zhu · 发表于：ACS Sensors · 年份：2025 · DOI：10.1021/acssensors.4c03072 · 被引用次数：22 · 研究领域：Conducting polymers and applications、Advanced biosensing and bioanalysis techniques、Electrochemical sensors and biosensors

Organic electrochemical transistor (OECT) sensors are a promising approach for point-of-care testing (POCT) thanks to their high sensitivity and ability to operate in an aqueous environment. However, OECTs suffer from biological fouling at the gate and channel interfaces when exposed to complex biological samples. These nonspecific interactions can often obscure the weak signal from the trace biomarker, compromising the accuracy and sensitivity of measurements and even leading to false detection outcomes. In this study, we developed an intrinsically antifouling OECT by modifying both the gate and channel with phosphorylcholine-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT-PC). This modification notably enhances the OECT performance by leveraging the material's inherent mixed electron-ion conductivity, which increases transconductance and decreases gate voltage. Additionally, the zwitterionic nature of the device enables its ultrasensitive detection of C-reactive protein (CRP) with a limit of detection of 0.11 pg/mL, mediated by calcium ions. This exceptional sensitivity arises from the device's enhanced transconductance and ability to sense through the gate and channel interfaces simultaneously. Furthermore, the zwitterionic OECT sensor has demonstrated the fastest sample-to-result time for protein detection (≤60 s), making it highly suitable for real-time CRP monitoring. Importantly, it provides precise real-time detection of CRP without interference from nonspecifi...