Glucose oxidation by enzyme takes place in neutral aqueous solution at room temperature, producing gluconic acid in equilibrium with gluconate, while gold catalysts exhibit much higher catalytic activity but in alkali solution to produce sodium gluconate. The combination of glucose oxidase with selected gold catalysts such as Au/ZrO2 and Au/NanoDiamond led to improved catalytic performance in neutral solution at room temperature. Gold nanoparticles supported on ZrO2 decomposed hydrogen peroxide (H2O2) formed by the oxidation of glucose and depressed the damage of glucose oxidase by H2O2. In addition, Au/ZrO2 utilized H2O2 produced by the enzyme to oxidize glucose to gluconic acid. In contrast, gold nanoparticles supported on NanoDiamond were active only for the decomposition of H2O2, while the presence of NanoDiamond itself could encourage glucose oxidase for the selective oxidation. (C) 2013 Elsevier B.V. All rights reserved.