Real-time electrochemical detection of Ascorbic acid in mouse brain homogenate using SCN-wrapped Co@NiO Nanosensor

Oxidative stress, a major key factor to neurological disorders such as Parkinson's, Alzheimer's, and Huntington's disease. Ascorbic acid (AA), a vital brain antioxidant, protects neurons by scavenging reactive oxygen species, and its fluctuations can damage neuronal function. Therefore, precise monitoring of AA in humans is critical for early diagnosis and disease management. However, despite significant advancements in noble metal-free nanocomposite based electrochemical sensors, precise detection remains challenging due to low physiological concentrations and interference from coexisting biomolecules, which limit sensor sensitivity, selectivity, and real-time applicability. To address these limitations herein, we synthesized cobalt-doped nickel oxide (Co@NiO), wrapped with thiourea, and dopamine (SCN- wrapped Co@NiO) for selective and sensitive detection of AA. The SCN groups provide abundant binding sites through hydrogen-bonding interactions with AA, thereby enhancing selectivity, while the Co@NiO nanostructure catalytically facilitates AA oxidation, significantly improving sensitivity and enabling efficient sensing efficacy against interfering species. The findings demonstrated that the fabricated material exhibits excellent sensitivity (0.1837 μA/nM/cm²), a wide linear range (5nM-20μM), and low detection limit (12.72 nM). Furthermore, the designed electrode has shown excellent selectivity towards AA even in presence of various interfering species, highlighting its potential in real-time analysis for practical applications.