A reversible fluorescence off-on-off sensor for sequential detection of aluminum and acetate/fluoride ions

A new rhodamine functionalized fluorogenic Schiff base CS was synthesized and its colorimetric and fluorescence responses toward various metal ions were explored. The sensor exhibited highly selective and sensitive colorimetric and off-on fluorescence response towards Al3+ in the presence of other competing metal ions. These spectral changes are large enough in the visible region of the spectrum and thus enable naked-eye detection. Studies proved that the formation of CS-Al3+ complex is fully reversible and can sense to AcO-/F- via dissociation. The results revealed that the sensor provides fluorescence off-on-off' strategy for the sequential detection of Al3+ and AcO-/F-. (C) 2015 Elsevier B.V. All rights reserved.