Electrochemical glucose sensors are vital for clinical diagnostics and the food industry, where accurate detection is essential. However, the limitations of glucose oxidase (GOx)-based sensors, such as complex preparation, high cost, and environmental sensitivity, highlight the need for non-enzymatic sensors that directly oxidize glucose at the electrode surface. In this study, a self-supporting hierarchical Cu/Fe₃O₄ nanosheet electrode was successfully fabricated by in situ growth on Ni Foam using a hydrothermal method, followed by annealing treatment. The Cu/Fe₃O₄ hierarchical nanosheet structure, with its large surface area, provides abundant active sites for electrocatalysis, while the strong interactions between Cu/Fe₃O₄ and Ni Foam enhance electron transfer efficiency. This novel electrode structure demonstrates exceptional electrochemical performance for non-enzymatic glucose sensing, with an ultrahigh sensitivity of 12.85 μA·μM⁻¹·cm⁻², a low detection limit of 0.71 μM, and a linear range extending up to 1 mM. Moreover, the Cu/Fe₃O₄/NF electrode exhibits excellent stability, a rapid response (~3 s), and good selectivity against interfering substances such as uric acid, ascorbic acid, H₂O₂, urea, and KCl. It also shows strong reliability in analyzing human serum samples. Therefore, Cu/Fe₃O₄/NF holds great promise as a non-enzymatic glucose sensor, and this work offers a valuable strategy for the design of advanced electrochemical electrodes.

Formaldehyde, a pervasive indoor air pollutant posing significant health risks, has driven extensive research into advanced mitigation strategies to ensure safer living environments. Herein, this study presents a synthesis method for the large-scale production of hydrogenated TiO₂ (P25) loaded with PtAu nanoalloys (P25(H)-PtAu), using a combination of ball milling and high-temperature annealing. Hydrogenation-induced defect-rich TiO₂ efficiently improves visible light absorption, enhancing the utilization of visible light in photocatalytic reactions. Mechanochemical ball milling was employed to prepare ultrasmall PtAu nanoalloys with a size of 3.7 ± 0.1 nm, which were uniformly dispersed on the surface of P25(H). Density functional theory (DFT) results indicate that PtAu nanoalloys synergistically enhance charge separation via Schottky junctions and surface reaction kinetics by optimizing reactant adsorption. As a result, P25(H)-PtAu achieves industrially relevant formaldehyde removal efficiency (97.8%) under ambient light conditions while maintaining scalability (10 g batches). This work provides a scalable framework for developing manufacturable photocatalysts, with immediate applications in heating, ventilation and air conditioning systems, and air purifiers.