A reversible turn-on colorimetric and fluorescent sensor for Al3+ in fully aqueous media and its living cell imaging

•A new julolidine-based fluorescent chemosensor L was prepared.•L exhibits a turn-on type fluorescence response toward Al3+ in aqueous medium.•The detection limit was as low as nano-molar level.•The probe could respond to Al3+ in a reversible manner.•L was employed for imaging the Al3+ ion in living biological cells.

A reversible fluorescent-colorimetric Schiff-base receptor (L) derived from julolidine and aminourea was developed for the selective sensing of Al3+ ions in buffered aqueous medium. Sensor L demonstrated the presence of Al3+ ions by both fluorescence enhancement and an instantaneous color change of solution from colorless to yellow. L forms complex with Al3+ in 1:1 ratio as supported by Job's plot analysis and mass spectroscopic measurement. The sensitivity of the fluorescent based assay (4.67 nM) for Al3+ is far below the WHO acceptable limit (7.41 μM) in drinking water. Furthermore, L was employed for imaging the Al3+ ion in living biological cells.

Graphical abstractA reversible fluorescent-colorimetric Schiff base receptor derived from julolidine and aminourea (L) was developed for the selective sensing of Al3+ ions in buffered aqueous solution. The sensitivity of the fluorescent based assay (4.67 nM) for Al3+ is far below the limit recommended in the WHO guidelines for drinking water (7.41 μM). The probe is very effective for detection of intracellular Al3+ through fluorescence microscopic imaging.Download high-res image (120KB)Download full-size image