Fluorescent probes are great tools for visualization and imaging of reactive oxygen species (ROS) in living cells. Although several probes perform well with green emission, however, to maximize tissue penetration and minimize interference from auto-fluorescence, a probe with longer wavelength is desirable. In this study, boron-dipyrromethene (BODIPY)-based fluorescent probe SB2 with high cell penetration and ROS selectivity, has been developed for detection of intracellular ROS. SB2 has two styryl groups anchored to the BODIPY pyrrole rings to extend the emission wavelength into the red region (657 nm) and also to act as a new receptor for ROS. In aqueous media, the probe demonstrated colorimetric change from blue to purple and orange fluorescence turn-on at 590 nm, selectively to hypochlorite, with the detection limit of 0.26 μM. The several oxidative intermediates were observed by mass spectrometry. Fluorescence detection with SB2 of endogenous ROS, in RAW264.7 macrophages, induced by lipopolysaccharide (LPS) or addition of exogenous NaOCl was observed in the orange field (570–620 nm).

荧光探针是用于可视化和成像活细胞中活性氧（ROS）的绝佳工具。尽管几种探针在发射绿色光时表现良好，但是为了使组织穿透最大化并最大程度地减少自发荧光的干扰，希望使用波长更长的探针。在这项研究中，已开发出具有高细胞渗透性和ROS选择性的基于硼二吡咯亚甲基（BODIPY）的荧光探针SB2，用于检测细胞内ROS。SB2具有两个固定在BODIPY吡咯环上的苯乙烯基，以将发射波长扩展到红色区域（657 nm），并且还充当ROS的新受体。在水性介质中，该探针在590 nm处比色从蓝色变为紫色和橙色荧光，并选择性地变为次氯酸盐，检测限为0.26μM。通过质谱观察到几种氧化中间体。在橙场（570-620 nm）中，观察到由脂多糖（LPS）或添加外源NaOCl诱导的RAW264.7巨噬细胞中内源性ROS的SB2荧光检测。