Photoluminescent Eu3+ has been doped into 100 and 200 nm diameter sizes of silica NS through a sol-gel synthesis route and use of a polymer bead template. Removing the polymer cores by calcination produces silica NS containing less than 3% mole europium, which emits a strong narrow red emission line at 615 nm. The long lifetime of the rare earth ion facilitates studies by 2-P microscopy. Two-photon microscopy of the europrium (III) doped NS show little interaction with HeLa cells in culture media; however, when the NS were coated with PEI they acquired a high positive charge and bound to the outer surface of HeLa cancer cells with minimal endocytosis. The ability to control nanoparticle location (cell surface versus interior) is valuable in biosensing and drug delivery studies.
A silica-stabilized nanoparticle was synthesized fromhydrophobic tris(dibenzoylmethane)-mono(phenanthroline) andtris(dibenzoylmethane)-mono(5-aminophenanthroline) europium(III)chelates in aqueous solution.
Journal of the Serbian Chemical Society