Taking cues from nature: Hemoglobin catalysed oxygen reduction

We describe experiments which elucidate the reaction mechanism of electrochemical oxygen reduction reaction (ORR) on a glassy carbon electrode modified with hemoglobin in an aqueous environment but with the hemoglobin physically separated from the electrode by a porous Nafion layer. Catalytic amplification of the current signal from the reduction of oxygen in a first electron transfer step is observed in the presence of hemoglobin immobilized within a Nafion coating. An overall four electron ORR mechanismis inferred and validated. (C) 2017 Elsevier Ltd. All rights reserved.