A highly sensitive enzymeless glucose sensor based on 3D graphene-Cu hybrid electrodes

We report a facile route to prepare the hybrid structure of 3 dimensional (3D) graphene and Cu and its uses for ultrahigh performance in enzymeless glucose detection. The graphene film was synthesized onto a 3D porous Ni foam substrate by chemical vapor deposition and a thin Cu layer was evaporated onto the 3D graphene/Ni foam by thermal evaporation. The structural and morphological properties of the Cu/3D graphene structure were characterized by X-ray diffraction, Raman spectroscopy, SEM and TEM. The developed sensor exhibited high selectivity towards glucose. We herein demonstrate that the Cu/3D graphene hybrid-based electrode has capability to deliver excellent cycling stability and it can detect glucose with an ultrahigh sensitivity of 7.88 mA mM^-1 cm^-2 and a detection limit of 18 nM (S/N = 8.6). The sensitivity value of our Cu/3D graphene hybrid is greater than any reported values of the materials. The superior long cycling stability and high sensitivity make the Cu/3D graphene hybrid promising for applications in the direct sensing of glucose.