Su Yang, Hao Li-Na, Liu Kun, Zhang Jun, Dong Liang, Xu Yunjun, Lu Yang, Qian Hai-Sheng
Department of Chemistry, Hefei University of Technology Hefei 230009 P. R. China
Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology Hefei 230009 P. R. China
RSC Adv. 2018 Apr 6;8(23):12944-12950. doi: 10.1039/c8ra01752b. eCollection 2018 Apr 3.
Upconversion core-shell nanoparticles have attracted a large amount of attention due to their multifunctionality and specific applications. In this work, based on a NaGdF sub-10 nm ultrasmall nanocore, a series of core-shell upconversion nanoparticles with uniform size doped with Yb, Er and NaDyF shells with different thicknesses were synthesized by a facile sequential growth process. NaDyF coated upconversion luminescent nanoparticles showed an obvious fluorescence quenching under excitation at 980 nm as a result of energy resonance transfer between Yb, Er and Dy. NaGdF:Yb,Er@NaDyF core-shell nanoparticles with ultrathin layer shells exhibited a better -weighted MR contrast.
上转换核壳纳米粒子因其多功能性和特定应用而备受关注。在这项工作中，基于直径小于10 nm的NaGdF超小纳米核，通过简便的连续生长过程合成了一系列尺寸均匀、掺杂Yb、Er且具有不同厚度NaDyF壳层的核壳上转换纳米粒子。由于Yb、Er和Dy之间的能量共振转移，NaDyF包覆的上转换发光纳米粒子在980 nm激发下显示出明显的荧光猝灭。具有超薄壳层的NaGdF:Yb,Er@NaDyF核壳纳米粒子表现出更好的纵向磁共振对比度。
