A viscosity-associated fluorescence turn-on probe for rapid local and topical tumor visualization

IR720 is a viscosity-associated near-infrared fluorescence turn-on probe that brightens in glycerol-rich media. It produces rapid cell-associated signals and allows imaging of pulmonary metastases and topically treated intestinal tumors. Exploratory limited proteolysis mass spectrometry identifies peptide-level changes in tumor tissue upon IR720 exposure.