Mitochondria Targeting Fluorescent Probes Based on Through Bond-Energy Transfer for Mutually Imaging Signaling Molecules H S and H O

Reactive signaling molecules participate in varieties of biochemical reactions, and methods to detect their mutual existence and crosstalk are in urgent demand. A benzothiadiazole-based handle was designed to fluorescently respond to the co-existence of H S and H O under pseudo-physiological conditions on a basis of a thiyl-radical-mediated mechanism that accounts for the rapid and efficient domino-like reaction processes. Then the handle motif was attached to a rhodamine moiety by means of an ethynylene linkage, and achieved a significant H S-H O mutual response in the mitochondria of living cells. Theoretical calculations supported that a through bond energy transfer mechanism contributes to the drastic fluorescence response.