ZIF in situ transformation hollow porous self-supporting CoZn-LDH@CuO electrode for electrochemical sensing of glucose and H2O2

A 3D hollow CoZn-LDH@CuO nanosheet array was prepared in situ by using CoZn-ZIF skeleton grown on Cu(OH)2 nanorods with copper foam as precursor. The catalyst materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray photoelectron spectroscopy (XPS). The synergistic effect between the three metals and the hollow layered nanosheet array structure make the catalyst have larger specific surface area and more exposed active sites, which can effectively improve the electron transfer rate. Using CoZn-LDH@CuO NSA/CF as the working electrode, glucose and H2O2 can be detected with sensitivity of 11,200 (μA mM−1 cm−2) and 4585 (μA mM−1 cm), respectively. The linear ranges were 2 μM − 3 mM and 0.8 μM − 3.5 mM and the detection limits is 0.17 μM (S/N = 3). The sensor had excellent stability, selectivity, fast response time (≤3 s), and the recoveries in the actual sample detection is 99.6 %-103.1 %. This strategy provides a new idea for the design and preparation of catalytic electrodes in the field of electrochemical sensing.