Light-activated nanozymes: catalytic mechanisms and applications

Recently, nanozymes have attracted enormous interest for their high stability, low cost and various enzyme-like activities. In nature, many biochemical reactions require light. Recently, introducing light to nanozymes has also been reported, especially for photosensitized oxygen activation. Compared to normal nanozymes, light-activated nanozymes possess several advantages including light-regulated activity, using molecular oxygen as a green oxidant, and often higher activity can be achieved. Herein, we summarize light-activated nanozymes, starting from their photophysical processes and identification of reactive oxygen species (ROS). Although the types of light-activated nanozymes are still quite limited and cannot yet mimic the same reactions as natural photo-related enzymes, they have widened the range of nanozymes. A few specific applications are highlighted, including sensing, chemical synthesis, degradation of organic pollutants, and cleavage and repair of DNA. Finally, a few future research opportunities are discussed.