Abstract:

Porous Ni(nickel foam, NF) self-supported electrodes modified by Cu₂O/Cu were fabricated by hydrothermal method. Their morphology and structure were characterized by X-ray diffraction(XRD) and field-emission scanning electron microscopy(FESEM). The resulted surface of porous Ni is completely covered with octahedral Cu₂O/Cu composites of different sizes. The maximum diameter of the octahedron is about 5 μm. The glucose catalytic oxidation activity of Cu₂O/Cu-NF was measured by cyclic voltammetry and constant potential amperometric method in alkaline medium with three-electrode system. The results show that the Cu₂O/Cu-NF fabricated at 150 ℃ has the strongest electrocatalytic activity. The linear relationship of response current and glucose concentration could be observed clearly in the range of 3.7×10^-3~1.1 mmol/L and 1.4~5.0 mmol/L, with sensitivity of 6929 μA/(mmol·L^-1·cm²) and 706.1 μA/(mmol·L^-1·cm²), respectively. Satisfyingly, the Cu₂O/Cu-NF electrode is successfully employed to eliminate the interferences from uric acid(UA), acid ascorbic(AA) and L-proline(L-P) during the catalytic oxidation of glucose. The response current of Cu₂O/Cu-NF electrode for glucose electrocatalytic oxidation could reach 91.6% of the original current after one month. The Cu₂O/Cu-NF electrode allows highly sensitive, excellently selective, stable, and fast amperometric sensing of glucose and thus is promising for the future development of nonenzymatic glucose sensors.

Key words: electrocatalysis, glucose oxidation, porous Ni self-supported electrode