Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University , Chengdu, Sichuan 610064, China.
Core Facility of West China Hospital, Sichuan University , Chengdu, Sichuan 610041, China.
Anal Chem. 2017 Sep 5;89(17):9544-9551. doi: 10.1021/acs.analchem.7b02613. Epub 2017 Aug 15.
Hypochlorous acid (HClO) acts as a dominant microbicidal mediator in the natural immune system, and the excess production of hypochlorites is related to a series of diseases. Thus, it is vitally important and necessary to develop a highly sensitive and selective method for HClO detection in living systems, and most of fluorescent probes are mainly focused on cells imaging. Besides, accurate HClO quantitative information about individual cells in a large cell population is extremely important for understanding inflammation and cellular apoptosis as well. In our work, a turn-on fluorescent probe has been synthesized, which can selectively and sensitively detect HClO with fast response time. The probe is almost nonfluorescent possibly due to both the spirolactam form of fluorescein and unbridged C═N bonds which can undergo a nonradiative decay process in the excited state. Upon the addition of ClO, the probe was oxidized to ring-opened fluorescent form and the fluorescence intensity was greatly enhanced. In live cell experiments, the probe was successfully applied to image exogenous ClO in HeLa cells and endogenous HClO in RAW 264.7 macrophage cells. In particular, the quantitative information on exogenous and endogenous HClO can also be acquired in flow cytometry. Therefore, the probe not only can image exogenous and endogenous HClO but also provides a new and promising platform to quantitatively detect HClO in flow cytometry.
次氯酸（HClO）在天然免疫系统中作为主要的杀菌介质发挥作用，而过氧化氯的过量产生与一系列疾病有关。因此，开发一种用于活系统中 HClO 检测的高灵敏度和选择性方法非常重要和必要，大多数荧光探针主要集中在细胞成像上。此外，对于理解炎症和细胞凋亡，了解单个细胞中 HClO 的准确定量信息对于了解炎症和细胞凋亡也非常重要。在我们的工作中，已经合成了一种开启型荧光探针，该探针可以选择性和灵敏地检测 HClO，具有快速的响应时间。探针几乎没有荧光，可能是由于荧光素的螺环酰胺形式和未桥接的 C═N 键在激发态下可以经历非辐射衰减过程。加入 ClO 后，探针被氧化为开环荧光形式，荧光强度大大增强。在活细胞实验中，该探针成功地用于 HeLa 细胞中外源 ClO 和 RAW 264.7 巨噬细胞内源 HClO 的成像。特别是，还可以通过流式细胞术获得对外源和内源 HClO 的定量信息。因此，该探针不仅可以成像外源和内源 HClO，还为流式细胞术定量检测 HClO 提供了一个新的有前途的平台。
