Graphene quantum dots as a new substrate for immobilization and direct electrochemistry of glucose oxidase: Application to sensitive glucose determination

► Electrochemistry of graphene quantum dots (GQDs) was studied in details. ► We developed a glucose biosensor based on GQDs-glucose oxidase modified electrode. ► The fabricated glucose biosensor exhibited remarkable analytical figure of merits. ► A GOx-GQD|CCE was developed for practical and routine clinical analysis.