Wearable\nFiber-Based Organic Electrochemical Transistors as a Platform for Highly Sensitive Dopamine Monitoring

Abstract

Fiber-based\norganic electrochemical transistors (FECTs) provide a new platform\nfor the realization of an ultrafast and ultrasensitive biosensor,\nespecially for the wearable dopamine (DA)-monitoring device. Here,\nwe presented a fully filament-integrated fabric, it exhibited remarkable\nmechanical compatibility with the human body, and the minimum sensing\nunit was an organic electrochemical transistor (OECT) based on PVA-<i>co</i>-PE nanofibers (NFs) and polypyrrole (PPy) nanofiber network.\nThe introduction of NFs notably increased the specific surface area\nand hydrophilicity of the PA6 filament, resulting in the formation\nof a large area of intertwined PPy nanofiber network. The electrical\nperformance of PPy nanofiber network-modified fibers improved considerably.\nFor the common FECTs, the typical on/off ratio was up to two orders\nof magnitude, and the temporal recovery time between on and off states\nwas shortened to 0.34 s. Meanwhile, the device exhibited continuous\ncycling stability. In addition, the performances of FECT-based dopamine\nsensors depending on different gate electrodes have also been investigated.\nThe PPy/NFs/PA6 filament-based dopamine sensor was more superior to\nthe gold and platinum (Pt) wires, and the sensor presented long-term\nsensitivity with a detection region from 1 nM to 1 μM, rapid\nresponse time to a set of DA concentrations, remarkable selectivity\nin the presence of sodium chloride, uric acid, ascorbic acid and glucose,\nand superior reproducibility. Moreover, it could also be woven into\nthe fabric product. The novel and wearable FECT device shows the potential\nto become the state-of-the-art DA-monitoring platform.