Combined Optical and MR Bioimaging Using Rare Earth Ion Doped NaYF 4 Nanocrystals

Abstract Here, novel nanoprobes for combined optical and magnetic resonance (MR) bioimaging are reported. Fluoride (NaYF 4 ) nanocrystals (20–30 nm size) co‐doped with the rare earth ions Gd 3+ and Er 3+ /Yb 3+ /Eu 3+ are synthesized and dispersed in water. An efficient up‐ and downconverted photoluminescence from the rare‐earth ions (Er 3+ and Yb 3+ or Eu 3+ ) doped into fluoride nanomatrix allows optical imaging modality for the nanoprobes. Upconversion nanophosphors (UCNPs) show nearly quadratic dependence of the photoluminescence intensity on the excitation light power, confirming a two‐photon induced process and allowing two‐photon imaging with UCNPs with low power continuous wave laser diodes due to the…

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  National Institutes of Health