Fluorescent schiff base probes for sequential detection of Al3+ and F- and cell imaging applications.

Two novel Schiff-base fluorescent probers SQ and NQ based on 8-hydroxyquinoline moiety were designed and synthesized. The both probes were capable of binding with Al3+ by naked eye detection to produce a significant fluorescence enhancement response with a detection limit of 1.48 × 10-8 and 4.23 × 10-8 M, respectively. At the same time, the formed complexes SQ-Al3+ and NQ-Al3+ could sequentially detect F-, and the detection limits of F- were determined to be 1.64 × 10-7 and 3.58 × 10-8 M, respectively. The "off-on-off" fluorescence response process demonstrated that the binding were reversible. The probes were further successfully utilized to detect Al3+ and F- in vitro PC12 cells.