The direct electrochemistry of glucose oxidase (GOx) integrated with graphene was investigated The voltammetric results indicated that GOx assembled on graphene retained its native structure and bioactivity exhibited a surface-confined process and underwent effective direct electron transfer (DET) reaction with an apparent rate constant (k(s)) of 2 68 s(-1) This work also developed a novel approach for glucose detection based on the electrocatalytic reduction of oxygen at the GOx-graphene/GC electrode The assembled GOx could electrocatalyze the reduction of dissolved oxygen Upon the addition of glucose the reduction current decreased which could be used for glucose detection with a high sensitivity (ca 110 +/- 3 mu A mM(-1) cm(-2)) a wide linear range (0 1-10 mM) and a low detection limit (10 +/- 2 mu M) The developed approach can efficiently exclude the interference of commonly coexisting electroactive species due to the use of a low detection potential (-470 mV versus SCE) Therefore this study has not only successfully achieved DET reaction of GOx assembled on graphene but also established a novel approach for glucose detection and provided a general route for fabricating graphene-based biosensing platform via assembling enzymes/proteins on graphene surface (C) 2010 Elsevier Ltd All rights reserved