A water-soluble two-photon fluorescent probe for rapid and reversible monitoring of redox state

Redox homeostasis is the guarantee for the normal operation of living organisms. Given its importance, monitoring dynamic changes of redox state will facilitate the study of relevant physiological and pathological processes. Herein, a two-photon fluorescent probe NA-Se with selenomorpholine as the response site has been developed for reversible detection of redox state. NA-Se exhibits outstanding analytical performance, including a rapid response to ClO − within 8 s, a detection limit as low as 13.3 nM, and at least 10 redox reversible cycles. Furthermore, NA-Se has improved water solubility and extremely low cytotoxicity, making it ideal for bioimaging. Finally, NA-Se has been successfully applied to monitor the ClO − /GSH redox cycle in living cells and zebrafish. This work may provide an effective tool for studying redox state and related diseases in vivo. • A redox reversible two-photon fluorescent probe NA-Se was designed and synthesized. • NA-Se has outstanding performance in response rate, reversibility, sensitivity, and biocompatibility. • NA-Se is capable of monitoring redox state in living cells and zebrafish. • NA-Se should contribute to the study of redox-related physiological and pathological processes.