Tuning the optical properties of BODIPY dye through Cu(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction

Borondipyrromethenes (BODIPY) are a class of fluorescent dyes whose fluorescence quantum yields are generally high and independent of the solvent. In this paper, we report the synthesis of a new type of BODIPY compound that carries an azido group on the 3-position of the pyrrole core. The azido group quenches the fluorescence of the dye due to its weak electron-donating effect. The fluorescence of the BODIPY dye can be switched on after reacting with alkynes via a Cu(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction. We further demonstrate that this azido-BODIPY compound can be used in the cell imaging applications.