Apoferritin–CeO2nano-truffle that has excellent artificial redox enzyme activity

4.5 nm nanoceria particles are successfully encapsulated into the apoferritin cavity via a dissociation–reconstruction route. The apoferritin coating not only improves the biocompatibility and changes the cellular uptake route of nanoceria, but also manipulates the electron localization at the surface of the nanoparticle thereby ameliorating the ROS-scavenging activity.