State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, China.
State Key Laboratory of Drug Research, Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
Chem Rev. 2023 Dec 27;123(24):13966-14037. doi: 10.1021/acs.chemrev.3c00401. Epub 2023 Nov 22.
Phosphorescence, characterized by luminescent lifetimes significantly longer than that of biological autofluorescence under ambient environment, is of great value for biomedical applications. Academic evidence of fluorescence imaging indicates that virtually all imaging metrics (sensitivity, resolution, and penetration depths) are improved when progressing into longer wavelength regions, especially the recently reported second near-infrared (NIR-II, 1000-1700 nm) window. Although the emission wavelength of probes does matter, it is not clear whether the guideline of "the longer the wavelength, the better the imaging effect" is still suitable for developing phosphorescent probes. For tissue-specific bioimaging, long-lived probes, even if they emit visible phosphorescence, enable accurate visualization of large deep tissues. For studies dealing with bioimaging of tiny biological architectures or dynamic physiopathological activities, the prerequisite is rigorous planning of long-wavelength phosphorescence, being aware of the cooperative contribution of long wavelengths and long lifetimes for improving the spatiotemporal resolution, penetration depth, and sensitivity of bioimaging. In this Review, emerging molecular engineering methods of room-temperature phosphorescence are discussed through the lens of photophysical mechanisms. We highlight the roles of phosphorescence with emission from visible to NIR-II windows toward bioapplications. To appreciate such advances, challenges and prospects in rapidly growing studies of room-temperature phosphorescence are described.
磷光，其特征是在环境条件下的发光寿命明显长于生物自发荧光，在生物医学应用中具有重要价值。荧光成像的学术证据表明，当进入更长的波长区域时，几乎所有的成像指标（灵敏度、分辨率和穿透深度）都得到了提高，特别是最近报道的第二个近红外（NIR-II，1000-1700nm）窗口。尽管探针的发射波长很重要，但目前尚不清楚“波长越长，成像效果越好”的准则是否仍然适用于开发磷光探针。对于组织特异性生物成像，长寿命探针，即使它们发射可见磷光，也能够实现大深度组织的精确可视化。对于研究微小生物结构或动态生理病理活动的生物成像，前提是要对长波长磷光进行严格规划，了解长波长和长寿命对提高生物成像的时空分辨率、穿透深度和灵敏度的协同贡献。在这篇综述中，我们通过光物理机制的视角讨论了室温磷光的新兴分子工程方法。我们强调了从可见到 NIR-II 窗口发射的磷光在生物应用中的作用。为了了解这些进展，我们描述了在快速发展的室温磷光研究中面临的挑战和前景。
