RE3+-Doped Ceria Nanoparticles with Spectroscopically Controlled ROS Scavenging Activity

Ceria (CeO
2-x
) and ceria-based nanoparticles (NPs) nowadays are well-known due to their unique enzyme-like catalytic activity making these materials indispensable for a number of biomedical applications. These NPs are more robust, more stable under extreme pH and temperature conditions and also much cheaper than natural enzymes. At the same time, as the mechanisms of anti-/prooxidant action of these NPs, so the ways to control their redox activity during interaction with ROS (reactive oxygen species) are discussed. We have obtained RE
³⁺
(RE = Y, Tb, Eu)-doped colloidal ceria nanoparticles revealing both luminescent and antioxidant properties. Luminescence endowed by RE
³⁺
doping of ceria nanoparticles was used for tracing the processes of ROS-nanoceria interaction using the methods of conventional optical spectroscopy. Ability of doped nanoceria for sensing and decomposition of hydrogen peroxide (HP) was shown, and the effect of various RE
³⁺
ions on the rate of HP decomposition and recovery of initial Ce
³⁺
/Ce
⁴⁺
ratio after HP decomposition was shown.