Graphene oxide severely inhibits DNase activity.

Graphene oxide (GO) is an important type of 2D nanomaterial and widely used in biomedicine, sensors, photocatalysis and electronic materials. With the extensive exposure of GO, its biological effect is debatable. In this study, we found a novel biological effect of GO, ie, suppression of deoxyribonuclease (DNase). GO inhibited DNA degradation when DNA or the DNA/RNA mixture was exposed to DNase. Moreover, GO suppressed nuclear fragmentation when the nuclei were treated with DNase. Interestingly, GO neither interacted with DNA nor influenced the interaction between DNase and DNA. Further investigation revealed that GO had a strong activity of adsorbing l-phenylalanine and l-histidine, key amino acid residues in the active site of DNase. These results suggest that GO could suppress the activity of DNase by interaction with the active site of DNase, and have an impact on DNase-related cellular processes (eg, apoptosis), implying its potential application in treating diseases associated with disorderly DNase function.