Self-supporting porous Cu₂O sensors with ultra-wide linear range for non-enzymatic glucose sensing

Copper-based materials are attractive for non-enzymatic glucose sensing due to their high activity and low cost. However, conventional powder-based electrodes often suffer from high interfacial resistance and limited active sites. Herein, we develop a facile strategy combining electrodeposition and anodization to directly fabricate self-supporting porous Cu₂O electrodes on copper foil. This binder-free electrode exhibits outstanding electrocatalytic performance, achieving a sensitivity of 946.19 μA·mM −1 ·cm −2 and a detection limit of 1.01 μM. Notably, it shows an exceptionally wide three-stage linear range (0.02–5.71 mM), covering physiological glucose levels in tears, saliva, interstitial fluid, and blood. The sensor also demonstrates excellent anti-interference ability and reproducibility, offering a promising approach for practical glucose detection.