Ligand-Free Synthesis of Tunable Size Ln:BaGdF5 (Ln = Eu3+ and Nd3+) Nanoparticles: Luminescence, Magnetic Properties, and Biocompatibility

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• 作者：Ana I. Becerro ; Daniel González-Mancebo ; Eugenio Cantelar ; Fernando Cussó ; Grazyna Stepien ; Jesús M. de la Fuente ; Manuel Oca?a
• 刊名：Langmuir
• 出版年：2016
• 出版时间：January 19, 2016
• 年：2016
• 卷：32
• 期：2
• 页码：411-420
• 全文大小：513K
• ISSN：1520-5827

文摘

Bifunctional and highly uniform Ln:BaGdF₅ (Ln = Eu³⁺ and Nd³⁺) nanoparticles have been successfully synthesized using a solvothermal method consisting of the aging at 120 °C of a glycerol solution containing the corresponding Lanthanide acetylacetonates and butylmethylimidazolium tetrafluoroborate. The absence of any surfactant in the synthesis process rendered hydrophilic nanospheres (with tunable diameter from 45 nm 85 nm, depending on the cations concentration of the starting solution) which are suitable for bioapplications. The particles are bifunctional because they showed both optical and magnetic properties due to the presence of the optically active lanthanides (Eu³⁺ in the visible and Nd³⁺ in the NIR regions of the electromagnetic spectrum) and the paramagnetic gadolinium ion, respectively. The luminescence decay curves of the nanospheres doped with different amounts of Eu³⁺ and Nd³⁺ have been recorded in order to determine the optimum dopant concentration in each case, which turned out to be 5% Eu³⁺ and 0.5% Nd³⁺. Likewise, proton relaxation times were measured at 1.5 T in water suspensions of the optimum particles found in the luminescence study. The values obtained suggested that both kinds of particles could be used as positive contrast agents for MRI. Finally, it was demonstrated that both the 5% Eu³⁺ and 0.5% Nd³⁺-doped BaGdF₅ nanospheres showed negligible cytotoxicity for VERO cells for concentrations up to 0.25 mg mL^–1.