Breaking Through the Signal-to-Background Limit of Upconversion Nanoprobes Using a Target-Modulated Sensitizing Switch
Breaking Through the Signal-to-Background Limit of Upconversion Nanoprobes Using a Target-Modulated Sensitizing Switch
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DOI：
10.1021/jacs.8b07329
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发表时间：
2018-11-07
影响因子：
15
通讯作者：
Liu, Zhihong
中科院分区：
文献类型：
--
作者：
Liang, Tao;Li, Zhen;Liu, Zhihong
镧系元素掺杂的上转换纳米粒子（UCNPs）由于其优异的物理化学性质，在生物传感和生物成像方面显示出了巨大的应用前景，但其信号背景比（SBR）的限制成为了研究人员开发上转换（UC）探针的瓶颈。由于UC纳米探针基本上用发光共振能量转移（LRET）过程来构建以提供“关-开”信号，因此SBR水平主要由发光猝灭效率决定，这很难通过现有方法进一步提高。在此，我们提出了一种新的策略，使用有机染料作为目标调制的敏化开关制作UC纳米探针。该染料既是靶点的识别单元，又是上转换发光（UCL）的潜在光敏剂。染料与目标的反应调节其物理化学性质，从而开启敏化作用并提供显著改善的SBR。该想法通过用于谷胱甘肽（GSH）检测的概念验证UC纳米探针进行验证，SBR类似于30（相对于大多数当前UC纳米探针的SBR小于10）。该探针在体外和体内均表现出良好的GSH传感性能。我们的研究结果表明，目标调制敏化是一个有用的新策略，以建立UC纳米探针。我们可以合理地预期，SBR极限的突破将使UC纳米探针在未来的研究中成为一个更强大的工具。
Although lanthanide-doped upconversion nanoparticles (UCNPs) have shown great promise in biosensing and bioimaging owing to their excellent photophysical properties, researchers are facing a bottleneck of upconversion (UC) probes which is the limited signal-to-background ratio (SBR). Since UC nanoprobes are basically constructed with a luminescence resonance energy transfer (LRET) process to provide "off-on" signals, the SBR level is principally decided by the luminescence quenching efficiency which is very difficult to further improve through existing approaches. Herein, we put forward a new strategy for fabricating UC nanoprobes using an organic dye as target-modulated sensitizing switch. The dye functions as both the recognition unit for target and a potential sensitizer for upconversion luminescence (UCL). The reaction of the dye with target modulates its photophysical properties, which switches on the sensitization and affords a significantly improved SBR. The idea is validated with a proof-of-concept UC nanoprobe for glutathione (GSH) detection with the SBR of similar to 30 (versus a SBR of less than 10 for most current UC nanoprobes). This probe showed good performance in GSH sensing both in vitro and in vivo. Our results indicate that the target-modulated sensitization is a useful new strategy to build UC nanoprobes. And we can reasonably expect that the breakthrough of SBR limit will make UC nanoprobe a more powerful tool in future studies.