Hierarchical cobalt nanorods shelled with nickel oxide vertically attached 3D architecture as non-binder and free-standing sensor for sensitive non-enzymatic glucose detection

Abstract

A hierarchical nanohybrid based on vertical cobalt oxide nanorods shelled with nickel oxide supported on a three-dimensional foam was prepared by a simple synthetic procedure. The unique nanoarchitecture along with superior conductivity and synergistic effect between components made hybrid become as a sensitive non-binder and free-standing sensor for non-enzymatic glucose detection at low concentration. In this regard, the hybrid exhibited excellent electrocatalytic activity towards glucose oxidation with a wide linear detection range of 1 μM to 2 mM, excellent sensitivity of 4.86 μA/(mM ⋅ cm2), low detection limit of 1.07 μM, and rapid response time of < 5 s in 0.1 M KOH. Furthermore, the hybrid displayed high selectivity to glucose without poisonous effect from common interferents, such as ascorbic acid, dopamine, uric acid, oxalic acid, urea, KCl, and Na2SO4. The results were therefore highly potential for the development of a novel sensor with the improved electrochemical performance towards glucose sensing applications.