A highly selective turn-on fluorescent probe for Al(III) based on coumarin and its application in vivo

In this study, a turn-on coumarin-based fluorescent probe, 7-hydroxy-6-[(2-hydroxy-naphthalen-1-ylmethylene)-amino]-4-methyl-chroman-2-one (CN), was developed for detecting Al3+ in aqueous systems. The binding ratio of CN-Al3+ complexes was determined from the Job plot and ESI-MS data to be 1 : 1. The binding constant (K-a) of Al3+ binding to CN was calculated to be 9.55 x 10(4) M-1 from a Benesi-Hildebrand plot and the detection limit was evaluated to be as low as 0.10 mu M (LOD = 3 sigma/slope). CN could be used as an effective fluorescent probe for detecting Al3+ in living HeLa cells. Moreover, CN could also be applied in the in vivo detection of Al3+ in zebrafish.