Highly efficient photo-driven generation and elimination of reactive oxygen species in biological environment by gold nanoclusters

Reactive oxygen species (ROS) play an essential role in cell signalling, pathogen defence, and maintaining cellular homeostasis. The photocatalysts are highly desired in the photo-driven in-situ ROS generation and elimination in biological environment. Here, we present the highly efficient photo-driven generation and elimination of ROS in biological environment by glutathione (GSH)-protected gold nanoclusters (AuNCs). In extracellular environment, AuNCs can generate hydrogen peroxide (H2O2) through a two-electron oxygen reduction reaction (ORR) without any additional sacrifices. On the other hand, in intracellular environment, AuNCs are capable of eliminating the ROS in cells under visible light. For the photocatalyst of GSH protected AuNCs, the photogenerated electrons are in response to reduction reactions, and meanwhile photogenerated holes can oxidize the GSH ligands, protecting other biomolecules from oxidation reactions. This work opens a new gate for the concentration manipulation of ROS in the biological environment as well as the real-time regulation of ROS in organisms.