A facile and efficient electrocatalytic oxidation of ascorbic acid by wheat peel extract employing controlled nanoflakes of NiCo₂O₄ nanostructures

Phytochemicals extracted from wheat peel were systematically investigated for their impact on non-enzymatic detection of ascorbic acid (AA) using NiCo₂O₄ nanostructures. These nanostructures were synthesized through a modified hydrothermal approach, utilizing varying concentrations of wheat peel extract (0.5 mL and 1 mL), which resulted in a notable morphological transformation from nanorods to porous nanoflakes. This transformation was confirmed through detailed analyses using scanning electron microscopy (SEM). Structural characterization, including X-ray diffraction (XRD) and selective area electron diffraction (SAED), further validated the cubic crystalline structure of the synthesized materials. Electrocatalytic performance assessments conducted in phosphate buffer solutions at a pH of 7.3 revealed a linear detection range for AA spanning from 0.1 mM to 20 mM, with an impressively low detection limit of 0.002 mM. Notably, NiCo₂O₄ nanostructures prepared with 1 mL of wheat peel extract demonstrated superior selectivity, stability, and reproducibility, making them highly suitable for real-world applications in AA quantification. The study emphasized the critical role of phytochemicals in altering the surface morphology and properties of NiCo₂O₄ nanostructures, thereby enhancing their selectivity and sensitivity for the development of non-enzymatic sensors. These findings represent a significant advancement in the development of accurate, cost-effective methodologies for monitoring ascorbic acid levels across various practical applications.