Electroreduction of dioxygen on Aunano–DNA film electrode in acidic electrolyte

The colloidal Au nanoparticles–deoxyribonucleic acid (Aunano–DNA) film modified glassy carbon electrode (GCE) has been fabricated and the electrochemical reduction of dioxygen (O2) at this modified GCE has been studied in 0.2 mol/L air-saturated acetate buffer (pH = 5.2) using cyclic voltammetry (CV), chronocoulometry (CC), linear scan voltammetry (LSV) and rotating disk electrode (RDE) as diagnostic techniques. The modified electrode shows excellent enhancement effect towards the reduction of dioxygen to hydrogen peroxide (H2O2), and the overpotential is lower than that at bare GCE. A well-defined dioxygen reduction peak appeared at about − 0.24 V. Based on experimental results, a reaction mechanism is proposed and discussed.