Near Infrared-Emitting Cr3+/Eu3+ Co-doped Zinc Gallogermanate Persistence Luminescent Nanoparticles for Cell Imaging

Qiaoqiao Wang; Shuyun Zhang; Zhiwei Li; Qi Zhu

doi:10.1186/s11671-018-2477-6

Near Infrared-Emitting Cr³⁺/Eu³⁺ Co-doped Zinc Gallogermanate Persistence Luminescent Nanoparticles for Cell Imaging

Nanoscale Res Lett. 2018 Feb 27;13(1):64. doi: 10.1186/s11671-018-2477-6.

Authors

Qiaoqiao Wang^{1

2}, Shuyun Zhang^{1

2}, Zhiwei Li^{1

2}, Qi Zhu^{3

4}

Affiliations

¹ Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, Liaoning, 110819, China.
² Institute of Ceramics and Powder Metallurgy, School of Materials Science and Engineering, Northeastern University, Shenyang, Liaoning, 110819, China.
³ Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, Liaoning, 110819, China. zhuq@smm.neu.edu.cn.
⁴ Institute of Ceramics and Powder Metallurgy, School of Materials Science and Engineering, Northeastern University, Shenyang, Liaoning, 110819, China. zhuq@smm.neu.edu.cn.

Abstract

Near infrared (NIR)-emitting persistent luminescent nanoparticles have been developed as potential agents for bioimaging. However, synthesizing uniform nanoparticles with long afterglow for long-term imaging is lacking. Here, we demonstrated the synthesis of spinel structured Zn₃Ga₂Ge₂O₁₀:Cr³⁺ (ZGGO:Cr³⁺) and Zn₃Ga₂Ge₂O₁₀:Cr³⁺,Eu³⁺ (ZGGO:Cr³⁺,Eu³⁺) nanoparticles by a sol-gel method in combination with a subsequent reducing atmosphere-free calcination. The samples were investigated via detailed characterizations by combined techniques of XRD, TEM, STEM, selected area electron diffraction, photoluminescence excitation (PLE)/photoluminescence (PL) spectroscopy, and temperature-dependent PL analysis. The single-crystalline nanoparticles are homogeneous solid solution, possessing uniform cubic shape and lateral size of ~ 80-100 nm. Upon UV excitation at 273 nm, ZGGO:Cr³⁺,Eu³⁺ exhibited a NIR emission band at 697 nm (²E → ⁴A₂ transition of distorted Cr³⁺ ions in gallogermanate), in the absence of Eu³⁺ emission. NIR persistent luminescence of the sample can last longer than 7200 s and still hold intense intensity. Eu³⁺ incorporation increased the persistent luminescence intensity and the afterglow time of ZGGO:Cr³⁺, but it did not significantly affect the thermal stability. The obtained ZGGO:Cr³⁺,Eu³⁺-NH₂ nanoparticles possessed an excellent imaging capacity for cells in vitro.

Keywords: Bioimaging; Nanoparticles; Near infrared (NIR)-emitting; Persistent luminescent; Spinel structure.