Oxygen vacancies boosted vanadium doped ZnO nanostructures-based voltage-switchable binary biosensor

The development of a reliable non-enzymatic multi-analyte biosensor is remained a great challenge for biomedical and industrial applications. In this prospective, rationally designed electrode materials having voltage switchable electrocatalytic properties are highly promising. Here, we report vanadium doped ZnO engineered nanostructures (Zn 1− x V x O where 0 ≤ x ≤ 0.1) which exhibit voltage switchable electrocatalytic properties for accurate measurements of glucose and hydrogen peroxide. Microstructures and chemical analysis show that the oxygen vacancies in the material can be tuned by controlling the stoichiometric ratios which play key role for voltage dependent measurements of different analytes. The developed Zn 1− x V x O nanostructures exhibit outstanding sensing ability for binary analytes with a high selectivity, low detection limit, thermal stability and long-term stability. The Zn 0.9 V 0.1 O/glassy carbon (GC) electrode shows 3-fold increase in reproducible sensitivity for both glucose (655.24 μ A mM −1 cm −2 ) and H 2 O 2 (13309.37 μ A mM −1 cm −2 ) as compared to the pristine ZnO/GC electrode. Moreover, the electrode also shows good response for human blood serum and commercially available samples. The results demonstrate that defect engineering is a promising route for the development of cost-effective non-enzymatic multi-analyte sensors for practical applications.