An Anion-Induced Hydrothermal Oriented-Explosive Strategy for the Synthesis of Porous Upconversion Nanocrystals

Peiyu Qiu, Rongjin Sun, Guo Gao^✉, Chunlei Zhang, Bin Chen, Naishun Yan, Ting Yin, Yanlei Liu, Jingjing Zhang, Yao Yang, Daxiang Cui^✉

Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Technology, Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, School of Electronic Information and Electrical Engineering, School of Mechanical Engineering, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See http://ivyspring.com/terms for full terms and conditions.

Citation:
Qiu P, Sun R, Gao G, Zhang C, Chen B, Yan N, Yin T, Liu Y, Zhang J, Yang Y, Cui D. An Anion-Induced Hydrothermal Oriented-Explosive Strategy for the Synthesis of Porous Upconversion Nanocrystals. Theranostics 2015; 5(5):456-468. doi:10.7150/thno.10946. Available from http://www.thno.org/v05p0456.htm

Abstract

Rare-earth (RE)-doped upconversion nanocrystals (UCNCs) are deemed as the promising candidates of luminescent nanoprobe for biological imaging and labeling. A number of methods have been used for the fabrication of UCNCs, but their assembly into porous architectures with desired size, shape and crystallographic phase remains a long-term challenging task. Here we report a facile, anion-induced hydrothermal oriented-explosive method to simultaneously control size, shape and phase of porous UCNCs. Our results confirmed the anion-induced hydrothermal oriented-explosion porous structure, size and phase transition for the cubic/hexagonal phase of NaLuF₄ and NaGdF₄ nanocrystals with various sizes and shapes. This general method is very important not only for successfully preparing lanthanide doped porous UCNCs, but also for clarifying the formation process of porous UCNCs in the hydrothermal system. The synthesized UCNCs were used for in vitro and in vivo CT imaging, and could be acted as the potential CT contrast agents.

Keywords: Hydrothermal, Anion-induced, Upconversion nanocrystals, Porous