Hydrogen-Substituted Graphdiyne Encapsulated Cu₂O Nanowires as Binder-Free Electrodes for Non-Enzymatic Glucose Sensing

The fabrication of electrochemical biosensors without any binder or enzymes is in high demand in the clinical diagnostic and industrial sectors. This work presents the development of hydrogen-substituted graphdiyne encapsulated Cu2O nanowires (Cu2O NWs@ HsGDY) hybrid electrode, directly grown on Cu foils. The sp and sp2 hybridization of HsGDY is confirmed by Raman and X-ray photoelectron spectroscopy, and the HsGDY encapsulation over Cu2O NWs is observed in transmission electron microscope images. The fabricated binder-free, nonenzymatic electrode exhibits the highest sensitivity of 584.2 μA·cm2·μM–1 (Cu2O NWs@HsGDY-1 h), the lowest detection limits of 0.035 μM (Cu2O NWs@HsGDY-6 h) and a linear detection range of 0.5–2500 μM. The Cu2O NWs@HsGDY-6 h electrode demonstrates 70 days of stability (82%) and excellent reproducibility (RSD = 1.97%) compared to other hybrid electrodes. The improved glucose sensing performance and stability is a combined effect of semiconducting nature and catalytic ability are attributed to Cu2O NWs@HsGDY hybrid electrodes. The successful glucose detection in actual food samples indicates the practical applicability of the Cu2O NWs@HsGDY sensor.