Mediatorless amperometric glucose biosensing using 3-aminopropyltriethoxysilane-functionalized graphene

► We develop a glucose oxidase biosensor for glucose free of exogenous mediator. ► It is achieved at −0.45 V applied potential vs. 3 M Ag/AgCl. ► This prevents signal interferences from other molecules and drug metabolites. ► Linearity of glucose signals ranged from 0.5 to 32 mM at pH 7.4. ► This covers the entire pathophysiological concentration of glucose in diabetics.