A Strategy for Simultaneously Realizing the Cubic-to-Hexagonal Phase Transition and Controlling the Small Size of NaYF4:Yb3+,Er3+ Nanocrystals for In Vitro Cell Imaging

Authors

  • Zhen-Ling Wang,

    1. Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR
    2. Analytical and Testing Center, Zhoukou Normal University, Wenchang Road, Zhoukou 466001, P. R. of China
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  • Jianhua Hao,

    Corresponding author
    1. Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR
    • Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR.
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  • Helen L. W. Chan,

    1. Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR
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  • Wing-Tak Wong,

    1. Department of Applied Biology and Chemistry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR
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  • Ka-Leung Wong

    1. Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR
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Abstract

original image

Hexagonal-phase NaYF4:Yb3+,Er3+ up-conversion nanocrystals (UCNCs) are synthesized by a combination of refluxing and hydrothermal treatment. This strategy leads to only a slight increase in particle size, from 4.5 to ca. 10 nm, during the cubic-to-hexagonal phase transition. The hexagonal UCNCs can be internalized by HeLa cells and exhibit visible emission in the cells under near-infrared excitation.

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