RGO Decorated N-doped NiCoO Hollow Microspheres Onto Activated Carbon Cloth for High-performance Non-enzymatic Electrochemical Glucose Detection

This paper reports the first effective fabrication of a high-performance non-enzymatic glucose sensor based on activated carbon cloth (ACC) coated with reduced graphene oxide (RGO) decorated N-doped urchin-like nickel cobaltite (NiCoO) hollow microspheres. Hierarchically mesoporous N-doped NiCoO hollow microspheres were synthesized using a facile solvothermal method, followed by thermal treatment in a nitrogen (N) atmosphere. Subsequently, they were hydrothermally decorated with RGO nanoflakes. The resulting composite was dip-coated onto ACC, and its electrochemical and glucose sensing performances were investigated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometric measurements in a three-electrode system. The composite electrode sensor demonstrates admirable sensitivity (6122 μM mM cm) with an ultralow detection limit (5 nM, S/N = 3), and it performs well within a substantial linear range (0.5-1.450 mM). Additionally, it exhibits good long-term response stability and outstanding anti-interference performance. These outstanding results can be attributed to the synergistic effects of the highly electrically conductive ACC with multiple channels, the enhanced catalytic activity of highly porous N-doped NiCoO hollow microspheres, and the large electroactive sites provided by its well-developed hierarchical nanostructure and RGO nanoflakes. The findings highlight the enormous potential of the ACC/N-doped NiCoO@RGO electrode for non-enzymatic glucose sensing.