文摘
Hydrophilic carbon clusters (HCCs) are oxidized carbon nanoparticles with a high affinity for electrons. The electron accepting strength of HCCs, employing the efficient conversion of superoxide (O<sub>2sub><sup>•–sup>) to molecular oxygen (O<sub>2sub>) via single-electron oxidation, was monitored using cyclic voltammetry and electron paramagnetic resonance spectroscopy. We found that HCCs possess O<sub>2sub> reduction reaction (ORR) capabilities through a two-electron process with the formation of H<sub>2sub>O<sub>2sub>. By comparing results from aprotic solvents to those obtained from ORR activity in aqueous media, we propose a mechanism for the origin of the antioxidant and superoxide dismutase mimetic properties of poly(ethylene glycolated) hydrophilic carbon clusters (PEG-HCCs).