One-pot hydrothermal synthesis of fluorophore-modified cerium oxide nanoparticles

Cerium oxide nanoparticles (CeO₂ NPs), which have powerful antioxidant properties, are promising nanomaterials for the treatment of diseases associated with oxidative stress. The well-developed surface of CeO₂ NPs makes them promising for use as a multifunctional system for various biomedical applications. This work demonstrates a simple approach that allows the direct formation of a molecular fluorophore on the surface of CeO₂ NPs using a simple one-pot hydrothermal synthesis. Thus, we were able to synthesize CeO₂ NPs of ultra-small size ∼2 nm with a narrow distribution, highly stable fluorescence, and a quantum yield of ∼62%. UV-visible transmission studies revealed that the resulting CeO₂ NPs exhibited fast autogenerative catalytic reduction. In vitro results showed high biocompatibility of CeO₂ NPs; their internalization occurs mainly in the region of cell nuclei. Thus, the resulting NPs have the necessary parameters and can be successfully used in biovisualization and therapy.