Luminescence lifetime imaging (LLIM) holds great promise in biomedical research owing to its excellent sensitivity and remarkable temporal–spatial resolution, but the development of effective long-lived luminescent probes for LLIM remains an unmet need. Herein, we designed two water-dispersible europium-doped nanoparticles (Eu-D1 and Eu-D2 NPs) for cellular LLIM, showing intense red luminescence emission and an increased lifetime of 4 orders of magnitude (∼56 000 times) than undoped NPs, which could be attributed to the multiple manipulations of their aggregation states, including efficient Förster resonance energy transfer (FRET), suppressed self-quenching, and restrained solvent effects. With good bioavailability, the as-developed NPs were demonstrated as reliable candidates for long-lifetime imaging agents. Such a simple and versatile strategy could be extended to develop various luminescent nanoprobes for advanced high-precision bioimaging.

中文翻译：

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铕掺杂纳米粒子通过聚合态的多重操作用于细胞发光寿命成像

发光寿命成像 (LLIM) 因其出色的灵敏度和显着的时空分辨率在生物医学研究中具有很大的应用前景，但为 LLIM 开发有效的长寿命发光探针仍然没有得到满足。在这里，我们为细胞 LLIM 设计了两种水分散性铕掺杂纳米粒子（Eu-D1 和 Eu-D2 NPs），显示出强烈的红色发光发射，并且比未掺杂的 NPs 寿命增加了 4 个数量级（~56000 倍），这可归因于对其聚集状态的多种操作，包括有效的 Förster 共振能量转移 (FRET)、抑制自猝灭和抑制溶剂效应。由于具有良好的生物利用度，所开发的纳米颗粒被证明是长寿命显像剂的可靠候选者。