A cyanine-derived near-infrared molecular rotor for ratiometric imaging of mitochondrial viscosity in cells

We developed a new cyanine-derived near-infrared (NIR) molecular rotor Mu1, which is superior to the traditional cyanines with high viscosity response, large Stokes shift (˜100 nm), and high photo-stability to detect the microscopic viscosity ratiometrically. The time-dependent density functional theory calculations highlighted the structure-optical properties of Mu1 as molecular rotor. Due to the mitochondria-actived fluorescence...