Highly sensitive electrochemical non-enzymatic glucose biosensor based on squamous NiCo₂O₄ nanosheets decorated nitrogen-doped reduced graphene oxide

Ultrathin and vertical NiCo₂O₄ nanosheets were grown on nitrogen-doped reduced graphene oxide (NiCo₂O₄ NSs@N-rGO) through a simple one-step co-precipitation procedure. The NiCo₂O₄ NSs@N-rGO nanocomposites were investigated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. And the performance of NiCo₂O₄NSs@N-rGO non-enzymatic glucose sensor was measured by cyclic voltammetry and amperometric method. The sensor exhibited two wide linear ranges of 0.01 mM-5.50 mM and 5.50 mM-15.50 mM with high sensitivity of 4372.9 μA·mM⁻¹cm⁻² and 1686.1 μA·mM⁻¹cm⁻², which is much better than other Co-based and Ni-based glucose sensors. In addition, the non-enzymatic glucose sensor also shows strong anti-interference and durability. Besides, it is found that this non-enzymatic glucose sensor can accurately measure the blood glucose concentration in human serum, which provides a great possibility for future application in medical treatment.