title: Rare-Earth-Based Nanoparticles with Simultaneously Enhanced Near-Infrared (NIR)-Visible (Vis) and NIR-NIR Dual-Conversion Luminescence for Multimodal Imaging.
abstract: Multifunctional NaGdF4 :Yb(3+),Er(3+),Nd(3+) @NaGdF4 :Nd(3+) core-shell nanoparticles (called Gd:Yb(3+),Er(3+),Nd(3+) @Gd:Nd(3+) NPs) with simultaneously enhanced near-infrared (NIR)-visible (Vis) and NIR-NIR dual-conversion (up and down) luminescence (UCL/DCL) properties were successfully synthesized. The resulting core-shell NPs simultaneously emitted enhanced UCL at 522, 540, and 660 nm and DCL at 980 and 1060 nm under the excitation of a 793 nm laser. The enhanced UCL and DCL can be explained by complex energy-transfer processes, Nd(3+) →Yb(3+) →Er(3+) and Nd(3+) →Yb(3+) , respectively. The effects of Nd(3+) concentration and shell thickness on the UCL/DCL properties were systematically investigated. The UCL and DCL properties of NPs were observed under the optimal conditions: a shell Nd(3+) content of 20 % and a shell thickness of approximately 5 nm. Moreover, the Gd:Yb(3+) ,Er(3+) ,Nd(3+) @Gd:20 % Nd(3+) NPs exhibited remarkable magnetic resonance imaging (MRI) properties similar to that of a clinical agent, Omniscan. Thus, the core-shell NPs with excellent UCL/DCL/magnetic resonance imaging (MRI) properties have great potential for both in vitro and in vivo multimodal bioimaging.
authors.affiliation: Department of Chemistry, School of Science, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Ma
authors.affiliation: Department of Chemistry, School of Science, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Chemistry, School of Science, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China. humin1971@mail.xjtu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: Institute of Biomedical Analytical Technology and Instrumentation, School of Life Science and Technology, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: The Biomedical-Information Engineering Laboratory of State Ministry of Education, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China.
authors.forename: Zhenxi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Diagnostic Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, ShaanXi Province, Xi'an 710061, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Chemistry, School of Science, Xi'an Jiaotong University, ShaanXi Province, Xi'an 710049, P.R. China. menglingjie@mail.xjtu.edu.cn.
authors.forename: Lingjie
authors.initials: L
authors.lastname: Meng
mesh_terms: D007259:Infrared Rays; D008027:Light; D049449:Luminescence; D008279:Magnetic Resonance Imaging; D053768:Metal Nanoparticles / Q000737:chemistry*; D008674:Metals, Rare Earth / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D008674:Metals, Rare Earth
keywords: core-shell structures; imaging agents; luminescence; nanostructures; upconversion