A Novel Hierarchical Flower-likeZnO@CuCo2O4Core-shell Nanorod Composites for Non-enzymatic Glucose Sensing

Abstract

Developing a highly sensitive enzyme-free glucose sensor is critical, given the significant health risks posed by diabetes. In this study, ZnO@CuCo2O4 composite with a novel flower-like heterostructure assembled by nanorods is prepared utilizing a straightforward hydrothermal process and calcination. The core-shell ZnO@CuCo2O4 featured by ZnO as the core and CuCo2O4 as the shell can improve the agglomeration phenomenon of CuCo2O4, expose more active sites, and promote efficient electron transfer. A ZnO@CuCo2O4 based non-enzyme glucose sensor is constructed and tested for the first time, which exhibits good sensing performance, a low limitation of detection of 0.82 μM, with broad linear ranges of 10–1725 μM and 1725–9225 μM, yielding sensitivities of 898 and 524 μA mM-1 cm-2, respectively, with a rapid response time of only 2 seconds. Furthermore, it shows excellent selectivity, long-term stability (retaining 92.42% of its initial response current after 20 days), and reproducibility, including in real saliva samples. The superior sensing performance of the ZnO@CuCo2O4 sensor can be attributed to the synergistic effects of the core-shell n-p heterostructure, the integration of amorphous and crystalline dual phases, and the flower-like architecture, which collectively optimize electron transfer and electrocatalytic activity. This work offers a cost-effective and innovative strategy for advancing enzyme-free glucose sensing technologies.