Combined Optical and MR Bioimaging Using Rare Earth Ion Doped NaYF4 Nanocrystals
Combined Optical and MR Bioimaging Using Rare Earth Ion Doped NaYF4 Nanocrystals
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DOI：
10.1002/adfm.200800765
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发表时间：
2009-03-24
影响因子：
19
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
--
作者：
Kumar, Rajiv;Nyk, Marcin;Prasad, Paras N.
在这里，新的纳米探针组合光学和磁共振（MR）生物成像的报告。合成了稀土离子Gd 3+和Er 3 +/Yb 3 +/Eu 3+共掺杂的氟化物（NaYF 4）纳米晶（尺寸为20-30 nm），并将其分散在水中。掺杂到氟化物纳米基质中的稀土离子（Er 3+和Yb 3+或Eu 3+）的有效上转换和下转换的光致发光允许纳米探针的光学成像模式。上转换纳米荧光粉（UCNPs）显示出光致发光强度对激发光功率的几乎二次依赖性，证实了双光子诱导过程，并由于双光子过程的顺序性，允许使用低功率连续波激光二极管使用UCNPs进行双光子成像过程。此外，UCNP和下转换纳米荧光体（DCNP）都用生物识别生物分子如抗密蛋白-4和抗间皮素修饰，并使用共聚焦显微镜显示体外靶向递送至癌细胞。还证明了使用纳米探针进行体内光学成像的可能性。还示出了纳米荧光粉内共掺杂的Gd 3+赋予用于高对比度MR成像的强T1（自旋-晶格弛豫时间）和T2（自旋-自旋弛豫时间）。因此，基于掺杂有稀土离子的氟化物纳米磷光体的纳米探针显示出提供光学和磁共振成像的双重模态。
Here, novel nanoprobes for combined optical and magnetic resonance (MR) bioimaging are reported. Fluoride (NaYF4) nanocrystals (20-30 nm size) co-doped with the rare earth ions Gd3+ and Er3+/Yb3+/Eu3+ are synthesized and dispersed in water. An efficient up- and downconverted photoluminescence from the rare-earth ions (Er3+ and Yb3+ or Eu3+) 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 sequential nature of the two-photon process. Furthermore, both UCNPs and downconversion nanophosphors (DCNPs) are modified with biorecognition biomolecules such as anti-claudin-4 and anti-mesothelin, and show in vitro targeted delivery to cancer cells using confocal microscopy. The possibility of using nanoprobes for optical imaging in vivo is also demonstrated. It is also shown that Gd3+ co-doped within the nanophosphors imparts strong T1 (Spin-lattice relaxation time) and T2 (spin-spin relaxation time) for high contrast MR imaging. Thus, nanoprobes based on fluoride nanophosphors doped with rare earth ions are shown to provide the dual modality of optical and magnetic resonance imaging.