Valence State and Oxygen Vacancy Engineering via Vanadium Doping in NiFe-LDHs for Highly Sensitive Non-enzymatic Glucose Detection

The growing global burden of diabetes necessitates the development of highly sensitive, stable, and cost-effective glucose-sensing technologies.Nonenzymatic electrochemical glucose sensors (NEGS) based on layered double hydroxides (LDHs) provide a durable and tunable alternative to enzyme-based sensors.Herein, we report a vanadium-doped nickel-iron LDH (NiFeV-LDH) system, hydrothermally grown on nickel foam, for enhanced glucose detection.Structural and spectroscopic analyses confirm that optimal vanadium incorporation (x = 0.4) modulates the lattice structure and defect chemistry, forming hierarchical nanoflowerlike architectures with enhanced electroactive surface area.These features facilitate enhanced Ni/Ni and V/V redox transitions, improving charge transport and glucose oxidation kinetics.The optimized NiFe.V.-LDHelectrode exhibits a high sensitivity of 1.891 mA mM cm, a low detection limit of 2.228 M, and excellent stability.This work highlights the synergistic role of valence-state engineering and defect modulation in designing advanced NEGS platforms, offering promising potential for future electrochemical sensing applications.