Confinement preparation of hierarchical NiO-N-doped carbon@reduced graphene oxide microspheres for high-performance non-enzymatic detection of glucose

Abstract

Here, hierarchical NiO-N-doped carbon@reduced graphene oxide (NiO-NC@rGO) microspheres have been fabricated by a confinement preparation process. Ni-based coordination polymer@rGO as precursor were synthesized by a simple hydrothermal method. Subsequently, NiO-NC microspheres were formed under the cover of rGO by pyrolysis. Morphology characterizations showed NiO-NC-rGO microspheres with a hierarchical structure based on ultrathin two-dimensional nanosheets. Most importantly, such microspheres exhibited excellent performances for the detection of glucose. The NiO-NC-rGO modified glassy carbon electrode (NiO-NC-rGO/GCE) was used as working electrode to establish a glucose sensor based on electrochemical technique. The main performance parameters of such glucose sensor are presented as follows. The sensitivity is 4254 μA mM−1 cm−2; The detection limit is 70.9 nM; The linear detection range is 0.5 μM − 20.0 μM (R = 0.9998). The structural and compositional advantages of NiO-NC@rGO have been considered in this work. On the one hand, the abundant active sites can be provided by the hierarchical structure of microspheres for the adsorption of the target molecules. On the other hand, the synergy of NiO, NC and rGO is the key design element of the ternary materials.