Constructing a fluorescent probe for specific detection of catechol based on 4-carboxyphenylboronic acid-functionalized carbon dots

Carbon dots (CDs) were covalently linked to 4-carboxyphenylboronic acid molecules to form the 4-carboxyphenylboronic acid molecules-functionalized CDs (CPBA-CDs). The CPBA functional groups, which were reactive toward vicinal diols, could covalently bridge the catechol with the vicinal diol structures and would cause the fluorescence quenching via the static quenching mechanism. As the concentration of catechol increased, the fluorescent signal gradually decreased. The fluorescent response for catechol detection was in the linear ranges from 0.1 to 56 μM with the detection limit of 115 nM. We further demonstrated that CPBA-CDs with good biocompatibility were easily and quickly internalized by human umbilical vein endothelial cells and are particularly suitable for multicolour real-time cellular imaging.