10.1021/acsami.6b02856.s001
Ying Li
Ying
Li
Yuyang Gu
Yuyang
Gu
Wei Yuan
Wei
Yuan
Tianye Cao
Tianye
Cao
Kai Li
Kai
Li
Shiping Yang
Shiping
Yang
Zhiguo Zhou
Zhiguo
Zhou
Fuyou Li
Fuyou
Li
Core–Shell–Shell NaYbF<sub>4</sub>:Tm@CaF<sub>2</sub>@NaDyF<sub>4</sub> Nanocomposites for Upconversion/T<sub>2</sub>‑Weighted MRI/Computed Tomography Lymphatic Imaging
American Chemical Society
2016
NaYbF
r 2 relaxivity
surface quenching effect
trimodal lymphatic bioimaging
upconversion
MRI
multifunctional contrast agent
core
HU
NaDyF 4 Nanocomposites
middle CaF 2 layer
NaDyF 4 nanocomposite
novel multifunctional nanoprobe
introduction
CT
Tm
nm
UCL
multimodality bioimaging
2016-07-01 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Core_Shell_Shell_NaYbF_sub_4_sub_Tm_CaF_sub_2_sub_NaDyF_sub_4_sub_Nanocomposites_for_Upconversion_T_sub_2_sub_Weighted_MRI_Computed_Tomography_Lymphatic_Imaging/3497663
To circumvent the defects of different
bioimaging techniques, the development of multifunctional probes for
multimodality bioimaging is required. In the present study, a lanthanide-based
core–shell–shell nanocomposite NaYbF<sub>4</sub>:Tm@CaF<sub>2</sub>@NaDyF<sub>4</sub> composed of an ∼9.5 nm NaYbF<sub>4</sub>:Tm nanocrystal as the core, ∼2 nm CaF<sub>2</sub> as
the middle layer, and 1–2 nm NaDyF<sub>4</sub> as the outermost
shell was designed and synthesized. Following surface modification
with the ligand, citrate acid, this nanocomposite was hydrophilic,
emitted intense upconversion luminescence (UCL), and displayed a high
X-ray computed tomography (CT) value of ∼490 Hounsfield units
(HU) and excellent <i>r</i><sub>2</sub> relaxivity of 41.1
mM<sup>–1</sup> s<sup>–1</sup>. These results confirmed
that the introduction of a middle CaF<sub>2</sub> layer was necessary
as a barrier to reduce cross-relaxation and the surface quenching
effect, thus enhancing the upconversion emission of Tm<sup>3+</sup>. This citrate-modified NaYbF<sub>4</sub>:Tm@CaF<sub>2</sub>@NaDyF<sub>4</sub> nanocomposite was used as a multifunctional contrast agent
for trimodal lymphatic bioimaging with T<sub>2</sub>-weighted magnetic
resonance imaging (MRI), CT, and UCL imaging. The concept of fabricating
a core–multishell nanostructure and the introduction of a Dy<sup>3+</sup>-based host as an outer layer is a useful strategy and can
be used to develop a novel multifunctional nanoprobe for multimodality
bioimaging.