Three-dimensional hybrid graphene/nickel electrodes on zinc oxide nanorod arrays as non-enzymatic glucose biosensors

•Structured electrochemical biosensor based on 3D hybrid ZnO nanorod/Ni nanoparticles/graphene nanosheets was fabricated.•The influence of graphene nanosheets on the performance of ZnO/Ni electrodes was shown.•The hybrid electrode showed a low detection limit with high electrocatalytic efficiency, sensitivity, stability, and glucose specificity.•The measured glucose values in the human blood serum correlated well with the reference.