Microflowers Comprised of Cu/CuxO/NC Nanosheets as Electrocatalysts and Horseradish Peroxidase Mimics

The preparation of various nanomaterials with hierarchical structure from metal-organic frameworks (MOFs) has attracted a lot of attention due to their abundant diversity in composition and structure. In this work, we developed a method to synthesize a three-dimensional (3D) Cu/CuxO/NC (nitrogen carbon) composite by pyrolysis of Cu-MOF. The obtained Cu/CuxO/NC composite has a flower-like structure assembled with nanosheets. It displays both excellent electrochemical catalytic and mimic enzyme activities. It was successfully applied to fabricate an electrochemical glucose sensor which has a linear response in the range of 0-2.0 mM and 2.0-5.0 mM with a detection limit of 3.5 mu M, and electrochemical measurements indicate that the Cu/CuxO/NC-modified electrode possesses high selectivity toward glucose. Moreover, Cu/CuxO/NC also acted as a horseradish peroxidase (HRP) mimic enzyme and displayed obvious enzymatic catalytic activities for tetramethylbenzidine (TMB) and dopamine (DA) in the presence of H2O2. To demonstrate the proof-of-concept, it was used to construct an enzymatic sensor for glucose. The obtained 3D Cu/CuxO/NC nanostructures present good prospects in sensor platform construction for other biomolecules.