Biocompatible fluorescent europium(III) magnetic nanoparticles

Silica-coated Iron oxide (Fe3O4@SiO2-NP) and silica (SiO2-NP) nanoparticles were prepared and derivatized with a Eu(III) complex to yield magneto-fluorescent (Fe3O4@SiO2-NP:C2) and fluorescent (SiO2-NP:C2) nanomaterials that could work as possible biosensors. The Fe3O4-NP core is inactive, although it contains an important property, magnetism, allowing particles to be directed to where they are needed. The Fe3O4@SiO2-NP:C2 and SiO2-NP:C2 (without magnetism) acted as fluorescent probes by means of an anchored europium (Eu) complex, which was used as fluorescence promoter, holding condensed aromatic ring as neutral ligands working as antenna - phenanthroline - that enhanced the fluorescence. The results showed that the cytotoxicity of the samples was almost inexistent, while fluorescent character was maintained unaltered in cellular medium for all the studied materials. This work provides new understandings through these nanomaterials for their potential application in imaging, representing a less toxic, more economically viable and sustainable solution, compared to existing ones.