Non-Enzymatic Glucose Sensor Based on Hierarchical Au/Ni/Boron-Doped Diamond Heterostructure Electrode for Improving Performances

A novel hierarchical Au/Ni/boron-doped diamond (BDD) heterostructure electrode was fabricated by two-step heat-treatment. The heterostructure that hierarchical Au/Ni nanoparticles are embedded on the surface of BDD was demonstrated by transmission electron microscope (TEM). Cyclic voltammetry (CV) and amperometric detection were used to test electrochemical properties of the prepared electrodes. The Au/Ni/BDD electrode exhibited enhanced catalytic activity and stability in glucose detection, as compared to that of the Au/BDD and Ni/BDD electrodes. On the optimal NaOH concentration and applied potential, the Au/Ni/BDD electrode exhibited an extremely wide detection range of 0.005-32 mM with high sensitivity of 1229.5 μAmM−1cm−2 and an excellent long-term stability (maintains 94.8% of initial current after one month). In addition, the prepared electrode also exhibited a low detection limit of 2 μM (S/N = 3), good selectivity and reproducibility. At last, the reasons for enhanced catalytic activity and excellent stability of Au/Ni/BDD electrode were discussed.