School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore, 637457, Singapore.
Nat Commun. 2019 May 2;10(1):2064. doi: 10.1038/s41467-019-10119-x.
Afterglow imaging with long-lasting luminescence after cessation of light excitation provides opportunities for ultrasensitive molecular imaging; however, the lack of biologically compatible afterglow agents has impeded exploitation in clinical settings. This study presents a generic approach to transforming ordinary optical agents (including fluorescent polymers, dyes, and inorganic semiconductors) into afterglow luminescent nanoparticles (ALNPs). This approach integrates a cascade photoreaction into a single-particle entity, enabling ALNPs to chemically store photoenergy and spontaneously decay it in an energy-relay process. Not only can the afterglow profiles of ALNPs be finetuned to afford emission from visible to near-infrared (NIR) region, but also their intensities can be predicted by a mathematical model. The representative NIR ALNPs permit rapid detection of tumors in living mice with a signal-to-background ratio that is more than three orders of magnitude higher than that of NIR fluorescence. The biodegradability of the ALNPs further heightens their potential for ultrasensitive in vivo imaging.
余晖成像是指在停止光激发后仍存在持久发光的现象，这为超高灵敏度的分子成像提供了机会；然而，缺乏生物兼容的余晖试剂限制了其在临床环境中的应用。本研究提出了一种将普通光学试剂（包括荧光聚合物、染料和无机半导体）转化为余晖发光纳米颗粒（ALNPs）的通用方法。该方法将级联光反应集成到单个粒子实体中，使 ALNPs 能够化学储存光能，并在能量传递过程中自发衰减。不仅可以精细调整 ALNPs 的余晖轮廓，以提供从可见光到近红外（NIR）区域的发射，还可以通过数学模型预测其强度。代表性的 NIR-ALNPs 可以在活小鼠中快速检测肿瘤，其信号与背景的比值比近红外荧光高三个数量级以上。ALNPs 的可生物降解性进一步提高了它们在超高灵敏度体内成像中的应用潜力。
