High-quality water-soluble and surface-functionalized upconversion nanocrystals as luminescent probes for bioimaging
High-quality water-soluble and surface-functionalized upconversion nanocrystals as luminescent probes for bioimaging
复制标题
高质量水溶性和表面功能化的上转换纳米晶体作为生物成像的发光探针
DOI：
10.1016/j.biomaterials.2010.12.050
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发表时间：
2011-04-01
期刊：
影响因子：
14
通讯作者：
Li, Fuyou
中科院分区：
文献类型：
--
作者：
Cao, Tianye;Yang, Yang;Li, Fuyou
稀土上转换纳米荧光粉（UCNPs）有很大的潜力成为荧光生物成像的优秀生物发光标记。然而，采用一步合成策略直接合成具有合适官能团的高质量水溶性UCNPs仍然很困难。在此，我们报告了一种利用二元配合配体（HR-BCL）辅助的水热反应一步合成高质量水溶性和表面功能化的UCNPs的策略。在该体系中，加入6-氨基己酸和油酸来控制小颗粒的核生成和晶体生长。合成的UCNPs具有高结晶性和强上转换发光特性。傅里叶变换红外光谱和核磁共振光谱分析表明，6-氨基己酸和油酸酯作为表面配体共同控制UCNPs的表面。因此，制备的UCNPs的水溶性可以通过改变6-氨基己酸与油酸的摩尔比来调节。aa修饰的UCNPs提供了（6.0 +/- 0.2）× 10(-5) mol/g的游离胺含量，这使得它们在水溶液中可分散，并允许进一步与叶酸（FA）偶联，用于靶向生物成像。此外，胺功能化的UCNPs表现出强烈的近红外上转换发光，并以高信噪比成功应用于小动物的淋巴毛细血管生物成像，表明这些表面功能化的UCNPs是发光生物标记物的有希望的候选物。(C) 2011 Elsevier Ltd.版权所有。
Rare-earth upconversion nanophosphors (UCNPs) have great potential to become excellent biological luminescent labels for fluorescence bioimaging. However, it is still difficult to directly synthesize high-quality water-soluble UCNPs bearing appropriate functional groups using a one-step synthetic strategy. Herein, we report a one-step synthetic strategy for high-quality water-soluble and surface-functionalized UCNPs using a hydrothermal reaction assisted by binary cooperative ligands (HR-BCL). In this system, 6-aminohexanoic acid and oleate were introduced to control nuclear generation and crystal growth of small nanoparticles. The UCNPs synthesized here showed high crystalline and intense upconversion luminescence emission. Fourier-transform infrared and nuclear magnetic resonance spectroscopy indicated that 6-aminohexanoic acid and oleate cooperate as surface ligands to co-control the surface of UCNPs. Thus, the water-solubility of the as-prepared UCNPs can be tuned by changing the molar ratio of 6-aminohexanoic acid to oleate. The AA-modified UCNPs provided a free amine content of (6.0 +/- 0.2) x 10(-5) mol/g, which renders them dispersible in aqueous solution and allows further conjugation with folic acid (FA) for targeted bioimaging. Furthermore, the amine-functionalized UCNPs show intense near-infrared upconversion luminescence and were successfully applied in the lymphatic capillary bioimaging of small animals with a high signal-to-noise ratio, suggesting that these surface-functionalized UCNPs are promising candidates for luminescent biolabels. (C) 2011 Elsevier Ltd. All rights reserved.