Fluorescent probes for ozone-specific recognition: An historical overview and future perspectives

Ozone (O3) is not only an environment pollutant at tropospheric or ground-level that poses a potential threat to human health, but it also belongs to the class of reactive oxygen species (ROS) which has been demonstrated to be deeply involved in significant physiological and pharmacological functions. Additionally, this reactive molecule has been widely applied in modern society, for example in air sterilization, and in both food and medical disinfection. Hence, effective detection methods for ozone in both the environment and in biological systems are a necessity. In recent years, the detection systems based on fluorescent strategy have manifested as promising methods for rapid, effective, and quantitative detection, specifically for the spatial and temporal sampling for in vivo bioimaging analysis. Despite a huge surge in the rationally-designed fluorescent probes for specific ROS, relatively limited attention has been paid to the fluorescent recognition of O3. Particularly, there is no systematic summarization for O3-specific fluorescent probes. In this review, a general overview was provided with the aim of summarizing the progress made so far in this subject. The chemical structures of the probes, and their sensing mechanisms with O3 and application in biological and environmental science are discussed in detail. Hopefully, this timely review can give useful information to the researchers in this field, resulting in this emerging area gaining more traction.