Batch-producible Fibrous Microelectrodes for Enzyme-Free Electrochemical Detection of Glucose

A facile method was developed in this work for the batch production of fibrous microelectrodes in enzyme-free electrochemical glucose sensors. The microelectrodes utilized carbon fibers (CFs) as the substrate and cobalt-containing metal organic framework, ZIF-67, as the electrocatalyst, which were mediated with reduced graphene oxide (rGO). The overall fabrication processes were carried out with carbon clothes and the fibrous ZIF-67/rGO/CF microelectrodes were extracted from the resulting composite, rendering a time-saving and economical batch-production approach. As the working electrode (WE) for electrochemical glucose detection, ZIF-67/rGO/CF manifested a wide linear detection range of 1–1000 μM, a low detection limit of 0.2 μM (S/N = 3), accompanied with the excellent selectivity and stability, which were comparable to the recently reported enzyme-free electrodes based on cobalt. A fibrous electrode based glucose sensor with ZIF-67/rGO/CF as the WE was further assembled, which showed reliable detection capability towards the glucose in serum and demonstrated the intriguing potential of ZIF-67/rGO/CF in practical applications.