CeO2 Nanoparticles for the Protection of Photosynthetic Organisms Immobilized in Silica Gels

Synthetic cytocompatible CeO 2 nanoparticles embedded in transparent silica hydrogels are useful for creating inorganic supports favoring the long-term entrapment of living Chlorella vulgaris cells. The key protective role of nanoparticles is twofold: (1) They efficiently absorb harmful UV radiation without scattering the useful visible one. (2) They limit oxidative stress damage, such as that induced by H 2 O 2 , thanks to the surface redox Ce 3+ -Ce 4+ reactivity of nanoparticles. © 2011 American Chemical Society.