title: Core-Shell-Shell NaYbF4:Tm@CaF2@NaDyF4 Nanocomposites for Upconversion/T2-Weighted MRI/Computed Tomography Lymphatic Imaging.
abstract: 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 NaYbF4:Tm@CaF2@NaDyF4 composed of an ∼9.5 nm NaYbF4:Tm nanocrystal as the core, ∼2 nm CaF2 as the middle layer, and 1-2 nm NaDyF4 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 r2 relaxivity of 41.1 mM(-1) s(-1). These results confirmed that the introduction of a middle CaF2 layer was necessary as a barrier to reduce cross-relaxation and the surface quenching effect, thus enhancing the upconversion emission of Tm(3+). This citrate-modified NaYbF4:Tm@CaF2@NaDyF4 nanocomposite was used as a multifunctional contrast agent for trimodal lymphatic bioimaging with T2-weighted magnetic resonance imaging (MRI), CT, and UCL imaging. The concept of fabricating a core-multishell nanostructure and the introduction of a Dy(3+)-based host as an outer layer is a useful strategy and can be used to develop a novel multifunctional nanoprobe for multimodality bioimaging.
authors.affiliation: The Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, Shanghai Normal University , Shanghai 200234, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, P.R. China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, P.R. China.
authors.forename: Tianye
authors.initials: T
authors.lastname: Cao
authors.affiliation: Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, P.R. China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: The Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, Shanghai Normal University , Shanghai 200234, P.R. China.
authors.forename: Shiping
authors.initials: S
authors.lastname: Yang
authors.affiliation: The Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, Shanghai Normal University , Shanghai 200234, P.R. China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, Fudan University , 220 Handan Road, Shanghai 200433, P.R. China.
authors.forename: Fuyou
authors.initials: F
authors.lastname: Li
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008221:Lymphoid Tissue / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D064847:Multimodal Imaging / Q000379:methods*; D053761:Nanocomposites; D053758:Nanoparticles / Q000737:chemistry; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media
keywords: core−shell−shell; lanthanide nanocomposite; lymphatic imaging; multimodality; upconversion luminescence