Acryl-modified diazabenzo[ghi]perylene for fast discrimination of Cys from GSH and Hcy with high quantum yield

A novel fluorescence probe (TIA) is designed and synthesized by grafting acryl on hydroxyl and diazabenzo[ghi]perylene, respectively. The acryl groups on hydroxyl act as a recognition site and fluorescence quencher. After a conjugated addition/cyclization reaction of Cys with TIA, the acryl groups on hydroxyl fall off and acryl conjugated perylene (TIA-OH) is released as the fluorophore with 70-fold increment of fluorescence in PBS. The short response time (less than 5 min) and high signal-noise-ratio endow the probe with fast detection, high sensitivity, low detection limit (0.11 mu M) and wide linear range (10-100 mu M). Interestingly, compared with the parent dihydroxy 1,2-diazabenzo[ghi]perylene, the introduction of acryl group on the perylene can modulate the fluorescence and increase the fluorescence quantum yield of TIA-OH by more than 10-fold (41 % in PBS). The TD-DFT calculations also reveal that the acryl group conjugated on the perylene can result intramolecular charge transfer and the calculated fluorescence is in good agreement with the experimental values. What's more, the high cell membrane permeability and specificity for Cys of the probe ensure the application in fluorescence imaging of living cells to detect intracellular Cys.