A non-enzymatic sensor based on three-dimensional graphene foam decorated with Cu-xCu2O nanoparticles for electrochemical detection of glucose and its application in human serum

In the present study, a porous structure consisting of three-dimensional graphene (3DG) decorated with Cu-based nanoparticles (NPs) (Cu or Cu–Cu₂O) was synthesized in order to develop an enzyme-free electrochemical glucose sensor. Moreover, the effects of Cu-based nanoparticle concentrations on electrochemical properties and glucose detection were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. Cu-based NPs@3DG showed markedly better electrochemical performance in glucose oxidation in alkaline solution compared to 3DG foam. Moreover, Cu–Cu₂O NPs@3DG foam with the lowest concentration of Cu precursor showed excellent performance in glucose detection. A high sensitivity of 230.86 μA mM⁻¹ cm⁻² was obtained for this electrode in a linear range of 0.8–10 mM (R² = 0.9951) and a detection limit of 16 μM. This sensor …