Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States.
Anal Chem. 2018 Oct 16;90(20):11785-11790. doi: 10.1021/acs.analchem.8b03104. Epub 2018 Oct 2.
The photostability of fluorescent probes is critical in biological imaging, especially for long-term observational analyses. Here, we describe a simple and universal method to improve the photostability of semiconducting polymer dots (Pdots) and other fluorescent probes by using buffers. Using Pdots as a model system, we found that HEPES or MES buffer can improve the photostability of Pdots by a factor of 20. Through a systematic study, we show that Pdot photobleaching is dominated by photoinduced radicals which can be quenched by the piperazine or morpholine structures of these buffers, which act as radical scavengers. For conditions where choice of buffer is limited, we designed fluorescent polymers conjugated with radical scavengers to improve Pdot photostability. We then demonstrate a practical application in which HEPES buffer is used to improve the photostability of Pdots during cell imaging.
荧光探针的光稳定性在生物成像中至关重要，特别是在长期观察分析中。在这里，我们描述了一种简单而通用的方法，通过使用缓冲液来提高半导体聚合物点（Pdots）和其他荧光探针的光稳定性。使用 Pdots 作为模型系统，我们发现 HEPES 或 MES 缓冲液可以将 Pdots 的光稳定性提高 20 倍。通过系统研究，我们表明 Pdot 的光漂白主要由光诱导自由基引起，这些自由基可以被缓冲液中的哌嗪或吗啉结构猝灭，从而起到自由基清除剂的作用。对于缓冲液选择受限的情况，我们设计了带有自由基清除剂的荧光聚合物，以提高 Pdot 的光稳定性。然后，我们在细胞成像中使用 HEPES 缓冲液来提高 Pdots 的光稳定性的实际应用中进行了演示。
