Recent advances in mitochondria-targetable organic molecule fluorescent probes for imaging of ROS

Abstract

Mitochondria, as the “energy power house” of the cell, utilize the oxygen to engage in oxidative phosphorylation accompanying production of triphosadenine (ATP), which will supply energy for the cell and organism. Meanwhile, various reactive oxygen species (ROS) will produce rapidly in mitochondria coupling with the electron leak in respiratory chain. The mitochondrial ROS plays important function in many processes, such as maintaining redox equilibrium, regulating cellular proliferation, differentiation and apoptosis. When the level of ROS exceeds the antioxidant defense capability of organism, various diseases will appear. Therefore, developing new methods to detect the level of ROS in mitochondria is of great importance for exploring the functional regulation effect of ROS. It’s still a huge challenge to accurately monitor ROS for chemistry, biology and medicine due to the properties of ROS, including low concentration, short lifetime and high reactivity. Fluorescence imaging is a powerful tool to track ROS in live cell and in vivo , because of its remarkable advantages, such as high temporal-spatial resolution, excellent biocompatibility and high sensitivity. In recent years, many fluorescent probes have been developed and applied for fluorescence imaging of ROS within mitochondria. In this review, we mainly summarize the progress of mitochondria-targetable organic small molecule fluorescent probes for detection of various ROS. Furthermore, future research directions for the construction of novel mitochondrial fluorescent probes as well as dissection of the cellular function of ROS by utilizing fluorescence imaging are prospected.