Oleylamine-Functionalized Graphene Oxide in Wearable Flexible Organic Field-Effect Transistors for Ultrasensitive NH₃ Detection

Organic field-effect transistors (OFETs) have demonstrated significant potential in wearable exhaled gas sensing due to their excellent mechanical flexibility, multiparameter measurement capabilities, and signal amplification advantages. However, combining excellent sensing performance with good mechanical robustness remains a key challenge that must be addressed in practical applications. In this study, we developed a flexible gas sensor by incorporating the elastomer styrene-ethylene-butylene-styrene to enhance the strain stability of the semiconductor layer. Additionally, the gas-sensing material oleylamine-functionalized graphene oxide was used to significantly improve the device's response to NH₃. The flexible sensor exhibits excellent sensing performance with outstanding selectivity for NH₃ in exhaled breath, demonstrating a high sensitivity of 67% ppm^-1 and a low theoretical limit of detection of 9.19 ppb. Moreover, it can be comfortably attached to human skin and retains high strain stability, maintaining excellent sensing performance even after tensile deformation. Therefore, with its robust detection capabilities and comfortable wearable features, this OFET-based gas sensor holds great promise for the auxiliary diagnosis of early-stage kidney diseases.