Luminescence enhancement of CaF 2 :Nd 3+ nanoparticles in the second near-infrared window for in vivo imaging through Y 3+ doping

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Materials for biology and medicine, 2018-02, Vol.6 (8), p.1238-1243
• Main Authors: Yu, Zhen-Feng, Shi, Jun-Peng, Li, Jin-Lei, Li, Peng-Hui, Zhang, Hong-Wu
• Format: Article
• Language: English
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/C7TB03052E

In vivo luminescent imaging in the second biological window (1000-1400 nm, NIR-II) has attracted increasing attention since it can provide high sensitivity to deep tissue in vivo imaging. Herein, we synthesized approximately 10-15 nm-sized NIR-II luminescent nanoparticles (CaF :Nd NPs). Furthermore, co-doped Y was utilized to enhance the NIR-II luminescence of the CaF :Nd NPs via breaking the aggregation of Nd . The appearance of a (200) diffraction peak and the broadening of the interplanar spacing of the (111) plane both showed that the incorporated Y can dissolve in CaF by occupying the Ca sites to form a CaF -YF solid solution. In particular, the addition of Y can greatly enhance the of the NIR-II luminescence of CaF :Nd NPs. When the Y doped concentration reached 0.30, the luminescence intensity of CaF :Y ,Nd NPs was about 65 times that of CaF :Nd NPs. In addition, the quantum yield of Ca Y Nd F NPs was 9.30% under the excitation of an 808 nm laser with 483 mW cm power, which was about 3 times higher than that of CaF :Nd NPs (3.10%). The in vivo imaging results revealed that the in vivo imaging intensity of Ca Y Nd F NPs was about 2.38-fold stronger than that of Ca F :Nd NPs. All of these results indicated that CaF :Y ,Nd NPs can be regarded as potential in vivo imaging probes for biological imaging.