Will the Bacteria Survive in the CeO 2 Nanozyme-H 2 O 2 System?

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H₂O₂), in which the nanozyme will promote the generation of ROS to kill bacteria based on the decomposition of H₂O₂. According to this criterion, a cerium oxide nanoparticle (Nanoceria, CeO₂, a classical nanozyme with high peroxidase activity)-based nanozyme-H₂O₂ system would be very efficient for bacterial disinfection. However, CeO₂ is a nanozyme with multiple enzyme-like activities. In addition to high peroxidase activity, CeO₂ nanozymes also possess high superoxide dismutase activity and antioxidant activity, which can act as a ROS scavenger. Considering the fact that CeO₂ nanozymes have both the activity to promote ROS production and the opposite activity for ROS scavenging, it is worth exploring which activity will play the dominating role in the CeO₂-H₂O₂ system, as well as whether it will protect bacteria or produce an antibacterial effect. In this work, we focused on this discussion to unveil the role of CeO₂ in the CeO₂-H₂O₂ system, so that it can provide valuable knowledge for the design of a nanozyme-H₂O₂-based antibacterial system. [ABSTRACT FROM AUTHOR]