Bifunctional and highly sensitive electrochemical non-enzymatic glucose and hydrogen peroxide biosensor based on NiCo2O4 nanoflowers decorated 3D nitrogen doped holey graphene hydrogel

Abstract

In this work, a simple strategy for fabricating a 3D nitrogen doped holey graphene hydrogel decorated with NiCo₂O₄ nanoflowers (NHGH/NiCo₂O₄) via a one-pot hydrothermal method with subsequent calcination is reported for the first time. The novel NHGH/NiCo₂O₄ nanocomposites featured high electrical conductivity, large and accessible surface areas, abundant active sites, and excellent electrocatalytic performance. Considering the excellent catalytic activity of NiCo₂O₄, a sensitive and bifunctional electrochemical non-enzymatic biosensor was established for the determination of glucose and hydrogen peroxide (H₂O₂). The obtained biosensor exhibited wide linear ranges (glucose: 0.005-10.95 mM; H₂O₂: 1-510 μM) and a low detection limits (glucose: 0.39 μM; H₂O₂: 0.136 μM) in alkaline solution (S/N = 3). Excellent electrocatalytic activity of this sensor was ascribed to the synergistic effects of the hybrid structure between the NiCo₂O₄ nanoflowers and NHGH. Furthermore, the sensitive biosensor also exhibited high selectivity and could be applied to determine glucose in real blood samples. Taken together, the results reveal that the proposed hybrid nanocomposite could be a promising electrochemical biosensor.

Keywords: Electrochemical sensor; Glucose; Hydrogen peroxide; NiCo(2)O(4) nanoflowers; Nitrogen doped holey graphene; Non-enzymatic.