Lanthanide-doped nanoparticles for hybrid x-ray/optical imaging

Date

2013-02-21

Department

Program

Citation of Original Publication

Sudheendra, L., Gautom K. Das, C. Li, Simon R. Cherry, and Ian M. Kennedy. “Lanthanide-Doped Nanoparticles for Hybrid x-Ray/Optical Imaging.” In Reporters, Markers, Dyes, Nanoparticles, and Molecular Probes for Biomedical Applications V, 8596:76–83. SPIE, 2013. https://doi.org/10.1117/12.2005250.

Rights

©(2013) Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

Subjects

Abstract

Some lanthanide-doped nanoparticles can absorb X-ray radiation and emit in the visible to near infrared spectrum via a down-conversion mechanism, making them a potentially valuable agent for in vivo imaging studies. We have studied a series of Gd³⁺ and Eu³⁺compositions in lanthanide fluorides to optimize the emission from Eu³⁺ upon X-ray excitation. The optimum concentration of Eu³⁺ that produced the most intense emission in NaGdF₄ was found to be 15% molar concentration. The impact of the crystallographic phases (i.e. cubic or hexagonal) on the optical emission was investigated. Furthermore, an attempt to include a sensitizer (i.e Ce³⁺) in NaGdF₄:Eu resulted in a reduction in the emission following X-ray excitation. A surface coating of NaGdF₄:Eu nanoparticles with a gold shell showed a similar decrease in luminescence intensity by a factor of two although the gold shell offers other advantages in biomedical applications.