Abstract: Fiber-based organic electrochemical transistors have broad application prospects in the fields of wearable electronic devices and biosensor due to the advantages of being flexible and wearable, low working voltage, high sensitivity, and good biocompatibility. In this study, cotton fiber was used as the raw material for electrodes, and graphene (Gr) and poly(3,4-ethylenedioxythiophene)-sodium polystyrene sulfonate (PEDOT:PSS) were used to modify the fiber surface to form a layer of PEDOT:PSS/Gr film on the fiber surface. The resistance of the PEDOT:PSS/Gr/fiber was as low as 60 Ω/cm. An organic electrochemical transistor device with stable output performance and high sensitivity was constructed by PEDOT:PSS/Gr/fiber, and shown good linear response to glucose detection in the range of 1 pM-500 nM, with a detection limitation of 1 pM. In addition, it is demonstrated that the sensor can resist interference from uric acid, ascorbic acid, and common metal ions (K+, Na+, Mg2+), which are common interferences in body fluids. The recovery rate was 104% -117% when used to detect saliva samples. This study can provide some technical support for non-invasive detection of blood glucose in diabetes.

Key words: Fiber-based organic electrochemical transistors, Sensor, Glucose, Non-invasive testing