Electrochemical detection of dioxygen and hydrogen peroxide by hemin immobilized on chemically converted graphene

Hemin molecules were immobilized onto chemically converted graphene (CCG) sheets through π–π stacking interaction to form a CCG–hemin composite. The composite modified electrode exhibited much higher electrochemical stability and stronger catalytic activity than those of hemin modified electrode. The potentials of dioxygen (O2) and hydrogen peroxide (H2O2) reduction reactions at CCG–hemin electrode were measured to be about 0.16 and 0.14 V higher than those at hemin electrode, respectively. Thus, this composite can be used for the fabrication of high-performance electrochemical sensors of O2 and H2O2.

► We studied the electrochemistry of hemin immobilized on chemically converted graphene (CCG). ► CCG improved the electrochemical stability and catalytic activity of hemin. ► The CCG–hemin composite modified electrode can be used to detect dioxygen and hydrogen peroxide.