title: Synthesis and functionalization of monodisperse near-ultraviolet and visible excitable multifunctional Eu(3+), Bi(3+):REVO4 nanophosphors for bioimaging and biosensing applications.
abstract: Near-ultraviolet and visible excitable Eu- and Bi-doped NPs based on rare earth vanadates (REVO4, RE = Y, Gd) have been synthesized by a facile route from appropriate RE precursors, europium and bismuth nitrate, and sodium orthovanadate, by homogeneous precipitation in an ethylene glycol/water mixture at 120 °C. The NPs can be functionalized either by a one-pot synthesis with polyacrylic acid (PAA) or by a Layer-by-Layer approach with poly(allylamine hydrochloride) (PAH) and PAA. In the first case, the particle size can also be tuned by adjusting the amount of PAA. The Eu- Bi-doped REVO4 based nanophosphors show the typical red luminescence of Eu(iii), which can be excited through an energy transfer process from the vanadate anions, resulting in a much higher luminescence intensity in comparison to the direct excitation of the europium cations. The incorporation of Bi into the REVO4 structure shifts the original absorption band of the vanadate anions towards longer wavelengths, giving rise to nanophosphors with an excitation maximum at 342 nm, which can also be excited in the visible range. The suitability of such nanophosphors for bioimaging and biosensing applications, as well as their colloidal stability in different buffer media of biological interest, their cytotoxicity, their degradability at low pH, and their uptake by HeLa cells have been evaluated. Their suitability for bioimaging and biosensing applications is also demonstrated.
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany and Instituto de Ciencia de Materiales de Sevilla, CSIC - Universidad de Sevilla. C. Américo Vespucio 49. E-41092, Seville, Spain. alberto.escudero@csic.es.
authors.forename: Alberto
authors.initials: A
authors.lastname: Escudero
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany and CIC biomaGUNE. Paseo Miramón 182. E-20009, San Sebastian, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Carrillo-Carrión
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany.
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Zyuzin
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany.
authors.forename: Sumaira
authors.initials: S
authors.lastname: Ashraf
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany.
authors.forename: Raimo
authors.initials: R
authors.lastname: Hartmann
authors.affiliation: Instituto de Ciencia de Materiales de Sevilla, CSIC - Universidad de Sevilla. C. Américo Vespucio 49. E-41092, Seville, Spain. alberto.escudero@csic.es.
authors.forename: Nuria O
authors.initials: NO
authors.lastname: Núñez
authors.affiliation: Instituto de Ciencia de Materiales de Sevilla, CSIC - Universidad de Sevilla. C. Américo Vespucio 49. E-41092, Seville, Spain. alberto.escudero@csic.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ocaña
authors.affiliation: AG Biophotonik, Fachbereich Physik, Philipps-Universität Marburg, Renthof 7. D-35037, Marburg, Germany.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Parak
mesh_terms: D015374:Biosensing Techniques; D005063:Europium; D006367:HeLa Cells; D006801:Humans; D049449:Luminescence; D010316:Particle Size; D014638:Vanadates
chemical_list: D014638:Vanadates; D005063:Europium