title: Seed-mediated synthesis of NaY F4:Y b, Er/NaGdF4 nanocrystals with improved upconversion fluorescence and MR relaxivity.
abstract: Rational combination of different functional lanthanide materials within a single nanocrystal presents a feasible way to develop a multifunctional nanoplatform for various biomedical applications. The conventional methods of synthesizing and integrating two kinds of material together generally involve laborious procedures, whilst codoping different functional ions inside a single lanthanide nanocrystal usually results in a decrease in both its fluorescence and its magnetic resonance relaxivity. Here, we present a seed-mediated synthetic route to prepare core-shell structured NaY F(4):Y b, Er/NaGdF(4) nanocrystals. Epitaxial growth of a gadolinium layer on an upconversion lanthanide seed not only improves its upconversion fluorescence, but also creates a paramagnetic shell with high magnetic resonance relaxivity. The prepared nanocrystals are uniform in size, stable in water and easy for conjugation after modification, which may have the potential to serve as a versatile imaging tool for smart detection or diagnosis in future biomedical engineering.
authors.affiliation: Department of Materials Physics, Zhejiang Normal University, Jinhua, Zhejiang, People's Republic of China.
authors.forename: Hai
authors.initials: H
authors.lastname: Guo
authors.forename: Zhengquan
authors.initials: Z
authors.lastname: Li
authors.forename: Haisheng
authors.initials: H
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: Idris Niagara
authors.initials: IN
authors.lastname: Muhammad
mesh_terms: D003287:Contrast Media / Q000737:chemistry; D004871:Erbium / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D005682:Gadolinium / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D017670:Sodium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D017670:Sodium Compounds; C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D004871:Erbium; D005682:Gadolinium; D005459:Fluorides