Oxidative damage of proteins or DNA strands induced by UV irradiation certainly brings inflammation, gene mutation, immunosuppression, even causes carcinogenesis to creatures. Here, we show that graphene oxide nanosheets (GONs) can significantly reduce the photosensitizer-mediated oxidative damage of proteins, caused by UV irradiation. GONs act as absorbers, physically shielding the proteins from UV light, but they participate in the photochemical reactions between photo-activated species and proteins as well. They quench transient species of photosensitizers by energy transfer and electron transfer, reduce highly toxic singlet oxygen yield and repair damaged protein residues. Our results may help revise and broaden previous findings concerning photochemical behavior and photo-biological effects of GONs. (C) 2016 Elsevier Ltd. All rights reserved.
