Electrocatalytic oxidation of glucose at gold nanoparticle-modified carbon electrodes in alkaline and neutral solutions

Electrocatalytic oxidation of glucose in alkaline and neutral solutions was examined using carbon electrodes modified with 2 nm core sized gold nanoparticles (Au-2 (nm) nanoparticle). The voltammetric responses for the electrocatalytic oxidation of glucose at Au-2 nm nanoparticle-modified electrodes in both alkaline and neutral solutions were similar to those at a gold plate electrode. However, the different results were obtained for the electrolysis of glucose between Au-2 (nm) nanoparticle-modified and gold plate electrodes. The current flow due to the oxidation of glucose during electrolysis at the, gold plate electrode decreased quickly with time, due to the electrode surface poisoning. On the other hand, the decrease in current flow at the Au-2 (nm) nanoparticle-modified electrode was much improved in both alkaline and neutral solutions. The electrolytic oxidation of glucose was performed at Au-2 (nm) nanoparticle modified electrodes in both alkaline and neutral solutions. In the alkaline solution, at a potential of -0.3 V, gluconolactone (or gluconate) was formed with a current efficiency of 100%, while at potentials of -0.1 to 0.3 V, oxalate and gluconolactone (or gluconate) were obtained as main products. In a neutral solution, electrolysis at 0.1 and 0.3 V, gluconolactone (or gluconate) was obtained with current efficiencies of 88-100%. (C) 2004 Elsevier B.V. All rights reserved.