Synthesis of NiCo-BTC MOFs-derived NiCo₂O₄ hollow microspheres for non-enzymatic glucose detection based on screen printing electrode

Blood glucose monitoring plays a critical role in diabetes diagnosis and management. This study presents a novel template-engaged strategy to fabricate NiCo₂O₄ hollow microspheres (NiCo-HMs) through thermal conversion of bimetallic organic frameworks (NiCo-BTC) precursors. The hierarchical architecture of NiCo-HMs provides an enlarged specific surface area for enhanced molecular accessibility, abundant exposed active sites from the bimetal synergistic system, and optimized electron transfer pathways through the interconnected porous network. When engineered into a portable biosensor (NiCo-HMs/SPE) via Nafion-assisted immobilization on screen-printed electrodes, the device demonstrates exceptional glucose sensing characteristics, including wide linearity (1.0 μM-2.0 mM, R² = 0.998), high sensitivity (789.4 μA·mM⁻¹·cm⁻²), rapid response (3.9 s)/recovery (6.4 s) kinetics, superior selectivity against common interferents, extended stability (90.0 % activity retention after 21 days). Practical validation was achieved through integration with a miniaturized potentiostat and smartphone interface, enabling real-time glucose tracking within ±15 % deviation thresholds. This MOF-derived hollow architecture provides new insights for developing next-generation wearable metabolic sensors.