Fe3+-codoped ultra-small NaGdF4:Nd3+ nanophosphors: enhanced near-infrared luminescence, reduced particle size and bioimaging applications

Yabing Li; Fujin Li; Yanan Huang; Haiyan Wu; Jian Wang; Jin Yang; Qingbo Xiao; Hongzhen Lin

doi:10.1039/c9ra00798a

Fe³⁺-codoped ultra-small NaGdF₄:Nd³⁺ nanophosphors: enhanced near-infrared luminescence, reduced particle size and bioimaging applications

RSC Adv. 2019 Jun 10;9(31):18070-18075. doi: 10.1039/c9ra00798a. eCollection 2019 Jun 4.

Authors

Yabing Li^{1

2}, Fujin Li², Yanan Huang², Haiyan Wu^{1

2}, Jian Wang^{1

2}, Jin Yang^{1

2}, Qingbo Xiao^{2

3}, Hongzhen Lin^{1

2}

Affiliations

¹ School of Nano Technology and Nano Bionics, University of Science and Technology of China Hefei Anhui 230026 China.
² i -Lab, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Sciences Suzhou 215123 China hzlin2010@sinano.ac.cn.
³ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences Fuzhou Fujian 350002 China.

Abstract

Small-sized lanthanide-doped nanoparticles (NPs) exhibiting superior near-infrared (NIR) luminescence properties are highly desired for bioimaging applications. Herein, Fe³⁺ ions are codoped in NaGdF₄:Nd³⁺ nanocrystals via a simple coprecipitation method, which can simultaneously reduce the particle size and enhance the downconverting NIR luminescence of the NPs. The NIR luminescence intensity reaches the maximum for the obtained sub-5 nm NPs when the doping concentration of Fe³⁺ is tuned to 20 mol%, which is ∼1.7 times higher than that of the pristine 8.7 nm NPs without Fe³⁺ doping. After being modified with targeting molecules, the ultra-small NaGdF₄:Nd³⁺,Fe³⁺ NPs were successfully applied as luminescent probes for targeted NIR imaging of tumors in biological tissues. Moreover, they also show great potential as a high contrast agent for T2-weighted MRI imaging.