Wearable and recyclable epinephrine biosensors based on molecular imprinting polymer modified organic electrochemical transistors

Tracking fluctuations of epinephrine level is essential for doctors or patients to evaluate the body's condition, but traditional epinephrine detection completely relies on the laboratory instrument. Herein, a wearable and recyclable epinephrine sensor based on the organic electrochemical transistor (OECT) has been developed for rapid, simple, and continuous detection. The molecular imprinting polymer (MIP) is modified on the gate electrode which can recognize the epinephrine molecules, and the voltage drop caused by redox of epinephrine will generate sensing signal. For epinephrine molecules, the boronate affinity binding in MIP and oxidation on electrodes make the sensor have great recyclability. The detection limit of this sensor is 10 pM, which is suitable for humoral metabolites. The sensor can be used for detection at least 20 cycles and recovered by the simple positive voltage cleaning, which is economical for wearable device. The flexible sensors units based on the polydimethylsiloxane (PDMS) are constructed with a matching portable circuit system connecting to the computer and mobile phone APPs. The whole wearable sensor puts up a user-friendly detection method with good recyclability, stability, selectivity and low detection limit for doctors or patients.