A novel near-infrared fluorescent probe for the imaging of viscosity in cells and tumor-bearing mice.

A near-infrared fluorescent probe (IC-V) for detecting viscosity is constructed. The probe has a large Stokes shift (170 nm) and an about 180-fold increase in fluorescence intensity at 700 nm. In addition, IC-V can not only distinguish cancer cells from normal cells, but also monitor viscosity in normal mice and tumor-bearing mice.