Holmberg Rebecca J, Aharen Tomoko, Murugesu Muralee
Centre for Catalysis Research and Innovation and Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5.
J Phys Chem Lett. 2012 Dec 20;3(24):3721-33. doi: 10.1021/jz301562m. Epub 2012 Dec 3.
Magnetic nanoparticles have been developed in recent years with applications in unique and crucial areas such as biomedicine, data storage, environmental remediation, catalysis, and so forth. NaYF4 nanoparticles were synthesized and isolated with lanthanide dopant percentages, confirmed by ICP-OES measurements, of Er, Yb, Tb, Gd, and Dy that were in agreement with the targeted ratios. SEM images showed a distinct variation in particle size and shape with dopant type and percentage. HRTEM and XRD studies confirmed the particles to be crystalline, possessing both α and β phases. Magnetic measurements determined that all of the nanoparticles were paramagnetic and did not exhibit a blocking temperature from 2 to 300 K. The multifunctional properties of these nanoparticles make them suitable for many applications, such as multimodal imaging probes, up-conversion fluorescent markers, as well as MRI contrast agents.
近年来，磁性纳米颗粒得到了发展，并应用于生物医学、数据存储、环境修复、催化等独特且关键的领域。合成并分离出了NaYF4纳米颗粒，通过电感耦合等离子体质谱（ICP-OES）测量确定了铒（Er）、镱（Yb）、铽（Tb）、钆（Gd）和镝（Dy）的镧系掺杂剂百分比，这些百分比与目标比例一致。扫描电子显微镜（SEM）图像显示，随着掺杂剂类型和百分比的变化，颗粒尺寸和形状有明显差异。高分辨率透射电子显微镜（HRTEM）和X射线衍射（XRD）研究证实这些颗粒是晶体，同时具有α相和β相。磁性测量确定所有纳米颗粒都是顺磁性的，在2至300 K范围内未表现出阻塞温度。这些纳米颗粒的多功能特性使其适用于许多应用，如多模态成像探针、上转换荧光标记以及磁共振成像（MRI）造影剂。
