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 Al 3+ , (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 Al 3+ in EtOH-H 2 O (v/v   =   1:9, pH   =   6) by forming a 1:1 complex with Al 3+ and the detection limit of QC for Al 3+ was as low as 0.012   μM. Furthermore, these results displayed that the binding of QC Al 3+ 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 Al 3+ . More importantly, QC was not only successfully used for the determination of trace Al 3+ in the tap water and the human blood serum, but was valid for fluorescence imaging of Al 3+ in the Hela cells.