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Controlled Synthesis of Uniform and Monodisperse Upconversion Core/Mesoporous Silica Shell Nanocomposites for Bimodal Imaging
Author(s) -
Liu Jianan,
Bu Wenbo,
Zhang Shengjian,
Chen Feng,
Xing Huaiyong,
Pan Limin,
Zhou Liangping,
Peng Weijun,
Shi Jianlin
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201102599
Subject(s) - nanocomposite , dispersity , materials science , photon upconversion , mesoporous silica , mesoporous material , nanotechnology , chemical engineering , sonication , nanoparticle , shell (structure) , bromide , fluorescence , optoelectronics , composite material , organic chemistry , chemistry , polymer chemistry , optics , luminescence , catalysis , physics , engineering
Here we report the design and controlled synthesis of monodisperse and precisely size‐controllable UCNP@mSiO 2 nanocomposites smaller than 50 nm by directly coating a mesoporous silica shell (mSiO 2 ) on upconversion nanocrystals NaYF 4 :Tm/Yb/Gd (UCNPs), which can be used as near‐infrared fluorescence and magnetic resonance imaging (MRI) agents and a platform for drug delivery as well. Some key steps such as transferring hydrophobic UCNPs to the water phase by using cetyltrimethylammonium bromide (CTAB), removal of the excess amount of CTAB, and temperature‐controlled ultrasonication treatment should be adopted and carefully monitored to obtain uniform upconversion core/mesoporous silica shell nanocomposites. The excellent performance of the core–shell‐structured nanocomposite in near‐infrared fluorescence and magnetic resonance imaging was also demonstrated.