Woven fiber organic electrochemical transistors based on multiwalled carbon nanotube functionalized PEDOT nanowires for nondestructive detection of potassium ions

Fiber based organic electrochemical transistors (FECTs) functionalized with poly(3, 4-ethylenedioxythiophene)/multiwalled carbon nanotube channel as transducer have been developed to detect ultralow concentration of potassium ions in the human body. Here, MWCNT increases the specific surface area and reaction sites of the cotton fiber, and induces a uniform and dense conductive network of PEDOT nanowires on the fiber, which greatly improves the performance of FECTs. In addtion, it can still maintain superior transistor performance under different bending degrees. The performance of ion sensors based on FECTs is systematically investigated. K+ can be detected in the range of 1–1000 nM with fast response and good reproducibility. Furthermore, the sensor combined with ion selective membrane has excellent anti-interference ability. The practical applicability of the sensor for K+ detection in artificial saliva has been verified. The sensors can also be integrated into fabric by hand-weaving, which providing a promising platform for convenient wearable healthcare monitoring.