Two-photon ratiometric imaging of endogenous reactive inorganic sulfur species in the cellular cushion toward formaldehyde

To address the potential biological relationship between reactive inorganic sulfur species (RISSs) and formaldehyde, the novel two-photon ratiometric RISSs probes (PH-RISSs) were synthesized practically with high selectivity and sensitivity toward RISSs and the related two-photon microscopic imaging assay was established which could be employed in the interpretation of the potential interaction between RISSs and formaldehyde. It was disclosed that the level of RISSs would raise toward formaldehyde and this behavior could be prohibited by CSE (cystathionine gamma lyase) inhibitor and reactive oxygen species (ROS) inhibitor, which indicated that formaldehyde could facilitate the metabolism of biothiols by CSE and this motivation of RISSs should be related with ROS intimately. Thus, RISSs might provide the critical biological compensation toward formaldehyde in a short term for living system and this two-photon ratiometric technique could be a practical tool to understand further the detailed interaction between aldehydes and RISSs in living systems. [Display omitted] •These ratiometric probes utilized classical starting materials to construct important two photon motif and showed potential AIE property.•These probes were provided excellent photophysical characterization toward RISSs.•The two photon ratiometric technique was established successfully to evaluate the level of RISSs in the living cell with excellent biocompatibility.•This assay convinced that formaldehyde could evoke responses (the rising level of RISSs)which could be inhibited by ROS inhibitor, such as DPI and NAC.