Simultaneous two-photon intravital imaging of viscosity and superoxide radical anion by a styrylpyridinium-based fluorescent probe.

Simultaneous sensing of cellular microenvironment parameters and redox signaling molecules by a single fluorescent probe allows an efficient access to numerous applications ranging from convenient diagnostic assays to investigation on their pathophysiological roles and cross-link. Focusing on a lack of efficient molecule tools for simultaneous intravital imaging of mitochondrial viscosity and superoxide radical anion (O 2 •-), we bridged diethylaminobenzene with diphenylphosphinate-modified pyridinium moiety by an olefinic bond to construct a styrylpyridinium-based two-photon fluorescent probe V-OS. V-OS triggered a turn-on response either at 625 nm to viscosity which blocks intramolecular rotation, or at 530 nm to O 2 •- via nucleophilic attack of O 2 •- followed by 1,6-elimination. With the aid of the two-photon probe, we not only identified the cross-talk between viscosity and O 2 •- but successfully mapped the burst of O 2 •- and the increased viscosity during either cellular ferroptosis process or cerebral ischemia reperfusion injury of living mice. [Display omitted] • Simultaneous imaging of mitochondrial viscosity and O 2 •- by a single fluorescent probe V-OS. • Turn-on response of V-OS to viscosity and O 2 •- at well-separated red and green channels. • Identifying the cross-talk between viscosity and O 2 •-. • Visualizing the generation of O 2 •- and the increased viscosity during cellular ferroptosis process. • Mapping the burst of O 2 •- and the increased viscosity during cerebral ischemia reperfusion injury in living mice. [ABSTRACT FROM AUTHOR]