A vertically aligned CuO nanosheet film prepared by electrochemical conversion on Cu-based metal-organic framework for non-enzymatic glucose sensors

Abstract

Constructing self-supported nanostructures on conductive substrates is an effective strategy to achieve non-enzymatic glucose sensors that possessing good reusability, reproducibility and stability. In the present study, vertical aligned CuO nanosheets on Cu foam are prepared with an in-situ electrochemical process including Cu-based metal-organic framework growing and subsequent electrochemical conversion. The scanning electron microscope results reveal that the totally electrochemical preparation guarantees the CuO nanosheets homogeneously free-standing on the Cu foam. The vertical aligned architecture endows the CuO/Cu electrodes good performances when using them as non-enzymatic glucose sensors, including a detection limit of 330 nM and a sensitivity of 33.95 mA cm−2 mM−1. We suggest that the facilitated ion transport in the vertical aligned architecture and the good conductivity originated from the totally electrochemical synthesis are responsible for the marked performances. More importantly, the good controllability of electrochemical preparation leads to remarkable reusability, reproducibility and stability of the electrodes, verified by multi-test of one electrode, consistency of multi-electrode and periodic test of one electrode in a long term. The practical detection of CuO/Cu electrodes on serum samples indicates the results are basically consistent with the clinical reports from hospital, further indicating their attractive potential in practical application.