A highly selective and sensitive turn-on probe for aluminum(III) based on quinoline Schiff's base and its cell imaging.

A reversible Schiff's base fluorescence probe for Al3+ , (3,5-dichloro-2- hydroxybenzylidene) quinoline-2-carbohydrazide (QC), based on quinoline derivative has been designed, synthesized and evaluated. The QC exhibited a high sensitivity and selectivity toward Al3+ in EtOH-H2 O (v/v=1:9, pH=6) by forming a 1:1 complex with Al3+ and the detection limit of QC for Al3+ was as low as 0.012μM. Furthermore, these results displayed that the binding of QCAl3+ was broken by F- , so this system could be used to monitor F- in the future. The enhancement fluorescence of the QC could be attributed to the inhibition of PET and ESIPT and the emergency of CHEF process induced by Al3+ . More importantly, QC was not only successfully used for the determination of trace Al3+ in the tap water and the human blood serum, but was valid for fluorescence imaging of Al3+ in the Hela cells.