Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China.
City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):2327-2335. doi: 10.1021/acsami.0c20757. Epub 2021 Jan 5.
This study presents a controlled synthesis of NaYbF@NaYF core-shell upconversion nanoparticles using the hot-injection technique. NaYF shells with tunable morphologies including long-rod, short-rod, and quasi-sphere are grown on identical NaYbF core nanoparticles by controlled injection of acetate or trifluoroacetate precursors. Mechanistic investigations reveal that anisotropic interfacial strain accounts for the preferential growth of shell layers along the -axis. However, the strain effect can be offset by the fast injection of shell precursors, leading to nearly isotropic growth of NaYF shells over the NaYbF core nanoparticles. The core-shell nanoparticles are further modified with DNA molecules and incubated with adenocarcinomic human alveolar basal epithelial cells. Based on a combination of characterizations by flow cytometry and confocal microscopy, favorable cellular uptake and DNA delivery are observed for the quasi-sphere nanoparticles, owing to the high dispersibility and easy membrane wrapping. The method described here could be extended to synthesize other types of functional nanostructures for the study of morphology-dependent properties.
本研究采用热注射技术，可控合成了 NaYbF@NaYF 核壳型上转换纳米粒子。通过控制醋酸盐或三氟醋酸盐前体的注入，在相同的 NaYbF 核纳米粒子上生长出了具有可调形态的 NaYF 壳层，包括长棒状、短棒状和准球型。机理研究表明，各向异性界面应变导致壳层优先沿[110]方向生长。然而，壳层前体的快速注入可以抵消应变效应，从而导致 NaYF 壳层在 NaYbF 核纳米粒子上几乎呈各向同性生长。核壳纳米粒子进一步用 DNA 分子修饰，并与腺癌细胞株人肺泡基底上皮细胞共孵育。基于流式细胞术和共聚焦显微镜的综合表征，准球型纳米粒子表现出良好的细胞摄取和 DNA 递送能力，这归因于其高分散性和易于膜包裹。这里描述的方法可以扩展到合成其他类型的功能纳米结构，以研究形态依赖性性质。
