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

•The CDs were functionalized with 4-carboxyphenylboronic acid molecules.•The functionalized CPBA-CDs were used to detect catechol via the surface quenching states induced mechanism.•The fluorescence quenching was because the phenylboronic acid formed boronate esters with vicinal diols. 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 56μM with the detection limit of 115nM. 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.