Two-photon imaging of hydrogen polysulfides in living cells and hippocampal tissues

Hydrogen polysulfide (H₂S_n) is an emerging topic of research because it plays a critical role in the pathological and physiological activities of an organism. Therefore, visual monitoring of H₂S_n activity in living cells is critical. In our work, a two-photon fluorescent probe NI-H₂S₂ based on a naphthalimide skeleton was developed as a molecular tool for detecting hydrogen polysulfides in solution and live HeLa cells. NI-H₂S₂ showed rapid response and high sensitivity. Notably, hydrogen polysulfides in hippocampal tissue of mice could also be tracked using the probe under a two-photon fluorescence microscope. Therefore, this probe NI-H₂S₂ is expected to serve as a pragmatic tool for studying the physiological roles of hydrogen polysulfides in living cells and in vivo.