Levels of reactive oxygen species (ROS) in cancer cells or in the tumor microenvironment differ noticeably from those in normal cells and cellular microenvironments because ROS play important roles in all aspects of tumor physiology. However, due to the lack of adequate tools, it is difficult to study the relationship between ROS, especially certain types of ROS (e.g., HOCl), and cancer. We report herein an HOCl-specific fluorescent probe, FDOCl-20, containing a thiocarbamide group as a receptor, for the visualization of HOCl in solid tumors in vivo. This probe displays high selectivity and sensitivity to HOCl, and is appropriate for use in acidic conditions, including the tumor microenvironment. Using FDOCl-20 as a tool, we can visualize HOCl in solid tumors in vivo. Importantly, the fluorescent intensity of FDOCl-20 is proportional to tumor volume. Thus, FDOCl-20 is a useful tool to investigate the relationship between HOCl and the physiological processes of tumors.

癌细胞或肿瘤微环境中的活性氧水平（ROS）与正常细胞和细胞微环境中的活性氧水平显着不同，因为ROS在肿瘤生理学的各个方面都发挥着重要作用。但是，由于缺乏适当的工具，因此难以研究ROS（尤其是某些类型的ROS，例如HOCl）与癌症之间的关系。我们在此报告了HOCl特异性荧光探针FDOCl-20，其中含有硫脲基作为受体，用于可视化体内实体瘤中的HOCl 。该探针显示出对HOCl的高选择性和敏感性，适合在酸性条件下使用，包括肿瘤微环境。使用FDOCl-20作为一种工具，我们可以可视化体内实体瘤中的HOCl 。重要的是，FDOC1-20的荧光强度与肿瘤体积成正比。因此，FDOC1-20是研究HOC1与肿瘤的生理过程之间的关系的有用工具。