Near-Infrared Mitochondria-Targetable Single-Molecule probe for Dual-Response of viscosity and sulfur dioxide in vivo

[Display omitted] •Dual-detection of viscosity and SO2 with different NIR fluorescence signals.•Both absorption and emission are in the near infrared region.•Large Stokes shift (95 nm) and low detection limit (0.24 μM).•Realizing the imaging in the living cells, zebrafish, and mice. Studies have demonstrated that the viscosity and SO2 in mitochondria are involved in various physiological processes, which are both important for maintaining the normal function of mitochondria. In this research, we rationally designed and synthesized a novel mitochondria-targetable fluorescent probe Mito-MG with near-infrared absorption and emission for dual-response of viscosity and SO2. Based on the TICT mechanism and Michael addition reaction, the probe Mito-MG responds to viscosity and SO2 with different near-infrared fluorescence signals. Importantly, Mito-MG presented outstanding mitochondrial targeting ability (Pearson’s colocalization coefficient is 0.8602) and has been successfully applied to imaging of the cells, zebrafish and mice. We believe that Mito-MG could be applied as a powerful tool for a deep understanding of the connection of viscosity and SO2 in biological systems.