Effects of Pt decoration on the electrocatalytic activity of nanoporous gold electrode toward glucose and its potential application for constructing a nonenzymatic glucose sensor

A nonenzymatic amperometric glucose sensor was fabricated based on the electrocatalytic oxidation of nanoporous gold (NPG) toward glucose. The NPG electrode was in situ prepared by a facile one-step square wave potential pulse (SWPP) treatment. The surface morphology of the NPG-based electrode was characterized by scan electron microscopy. Voltammetry and amperometric methods were used to evaluate the electrocatalytic activities of the NPG-based electrodes toward the glucose oxidation in both neutral and alkaline media. The NPG electrode showed a quick and sensitive response to glucose. The electrocatalytic activity of NPG in neutral condition was further improved when a small amount of Pt was decorated on NPG (NPG–Pt). When applied for glucose sensing, the NPG–Pt electrode showed a linear range of 0.5–10 mM with a sensitivity of 145.7 μA cm−2 mM−1 and a detection limit of 0.6 μM (S/N = 3). The physiological levels of ascorbic acid (0.1 mM) and uric acid (0.02 mM) only had negligible interferences to the glucose detection. The high sensitivity and selectivity of the present sensor was due to the high roughness factor of the electrode surface and unique electrooxidation mechanism of glucose. In addition, the present nonenzymatic glucose sensor was easy in preparation and very stable.