Magnetic/upconversion luminescent mesoparticles of Fe3O4@LaF3:Yb3+, Er3+ for dual-modal bioimaging

Abstract

Multifunctional magnetic/upconversion luminescent mesoparticles, consisting of a Fe(3)O(4) nanoparticle core and a LaF(3):Yb(3+), Er(3+) nanocrystal shell, have been developed using a facile co-precipitation approach. Owing to their excellent superparamagnetic properties, superior T(2)-enhanced magnetic resonance effect and strong upconversion emissions, the as-formed mesoparticles have great potential in diverse medical diagnostics and biological imaging.

Synthesis of YF3: Yb, Er upconverting nanofluorophores using chitosan and their cytotoxicity in MCF-7 cells

“…Polymeric nanoparticles and their composites have been used in targeted drug delivery, gene therapy and other biomedical applications such as photodynamic therapy, magnetic resonance imaging and bioimaging [5][6][7][8][9]. The toxicity of the nanoparticles mainly depends on the size, shape, composition and properties of the surface [10][11][12].…”

Optical/Magnetic Multimodal Bioprobes Based on Lanthanide‐Doped Inorganic Nanocrystals

“…Integrating fluorescence imaging and MRI contrast enhancement into a single NP is a common strategy of the multimodal imaging. [24, 36, 38e, 52] Currently several groups realized optical and MR dual-modal imaging by employing Ln 3 + -doped NPs, exemplified by Fe 3 O 4 @LaF 3 :Yb/Er, [10] NaYF 4 :Yb/Er/Gd, [34,36] and Gd 2 O 3 :Yb/Er, [20a] to name a few. Among them, coreshell structured multimodal NPs that are composed of iron oxides and Ln 3 + -doped UC NPs are widely used in optical and MR dual-modal imaging.…”

“…A common strategy is to construct a core-shell structure that consists of luminescent and magnetic materials. However, these hybrid composites (such as Fe 3 O 4 @NaLuF 4 :Yb/Er [9] and Fe 3 O 4 @LaF 3 :Yb/Er [10] ) often confront the difficulties in combining individual optical or magnetic functions while preserving the original particle sizes. To solve this problem, some single-phase nanomaterials like Gd 3 + -based NPs (such as KGdF 4 :Tm/Yb [11] and NaGdF 4 :Er/Yb [12] ) have recently been proposed as a new class of multimodal bioA C H T U N G T R E N N U N G probes, as Gd 3 + is not only a paramagnetic relaxation agent owing to its seven unpaired electrons of the half-filled 4f shell, but is also an efficient sensitizer that can transfer the excitation energy to activate the neighboring Ln 3 + emitters.…”

“…[25] The method has several advantages including the possibility of tuning the coating thickness and corresponding optical or magnetic properties. Through the layer-by-layer coating method, an important class of coreshell structured multimodal NPs can be synthesized, where iron oxides such as Fe 3 O 4 are employed as the magnetic units and Ln 3 + -doped UC NPs served as fluorescent units, for instance, NaYF 4 :Yb/Tm@Fe x O y , [26] Fe 3 O 4 @NaYF 4 :Yb/ Er, [27] Fe 3 O 4 @NaLuF 4 :Yb,Er/Tm, [9] and Fe 3 O 4 @LaF 3 :Yb/ Er [10] NPs. The T 2 (spin-spin relaxation time) magnetic resonance properties result from the superparamagnetic iron oxide (Fe 3 O 4 ), and the excellent upconversion (UC) emissions arise from Ln 3 + -doped fluorides.…”

Synthesis, Characterization and Cytotoxicity of Novel Multifunctional Fe3O4@SiO2@GdVO4:Dy3+ Core-Shell Nanocomposite as a Drug Carrier

“…In these reports [8,9,10,11,12], if the lanthanide-doped nanomaterials are chosen as cores, their luminescent intensity may be suppressed to some extent due to the coating of the outer layers. Meanwhile, if the lanthanide-doped nanomaterials are in direct contact with Fe 3 O 4 , their luminescence may be decreased as the direct contact can cause fluorescence-quenching [13,14,15].…”