Simultaneous bioimaging recognition of Al3+ and Cu2+ in living-cell, and further detection of F- and S2- by a simple fluorogenic benzimidazole-based chemosensor.

A simple Schiff base (BMSA) prepared from salicylaldehyde and 2-(1H-benzo[d]imidazol-2-yl)aniline was evaluated as an efficient fluorescent chemosensor for the selective recognition of Al3+and Cu2+ over other common metal ions. This sensor could detect Al3+ in CH3OH/PBS with distinct emission red-shift (the detection limit 0.31μM)and Cu2+in CH3OH/Tris-HCL (the detection limit 0.54μM) with obvious fluorescence quenching. The obtained BMSA-Al3+ and BMSA-Cu2+ complexes could act as cascade sensors for detecting F- and S2-, respectively. The recognizing behavior of BMSA toward Al3+and Cu2+ has been investigated in detail through Job's Plot, FT-IR NMR, and HRMS analysis. Moreover, this chemosensor was verified to be of low cytotoxicity and good imaging characteristics for the detection of Al3+ and Cu2+, and further for the recognition of F- and S2- in living cells, suggesting that BMSA was proved to be a useful tool for tracking Al3+/Cu2+and F-/S2- ions in vivo.