A fluorescence turn-on probe for human (bovine) serum albumin based on the hydrolysis of a dioxaborine group promoted by proteins

A fluorescence off-on'' probe CBF, constructed by incorporating a dioxaborine unit into a microenvironment-sensitive fluorophore, was developed for serum albumin (SA). Upon binding to SA, the dioxaborine group in CBF was hydrolyzed into beta-diketonate, which triggered dramatic fluorescence enhancement (over 1000-fold) along with a remarkable blue-shift (similar to 100 nm). The bioimaging results suggested that more SA were taken in by cancer cells.