meso-ester BODIPYs for the imaging of hypoxia in tumor cells

We report the p-nitrobenzyl ester of a meso-carboxyl BODIPY as a new fluorogenic probe for the monitoring of nitroreductase acitivity. It showed remarkable fluorescence enhancement (∼220-fold), high sensitivity (detection limit of 0.9 ng/mL), and high selectivity for nitroreductase over other biorelated species. In vitro cell studies confirmed its utility for the rapid fluorescence imaging of hypoxic cancer cells.