Anthracene- and pyrene-bearing imidazoles as turn-on fluorescent chemosensor for aluminum ion in living cells

A newly designed 2-(2-Aminophenyl)-1H-benzimidazole integrated anthracene/pyrene derivatives as efficient chemosensors were synthesized. The probes N-(anthracen-9-ylmethylene)-2-(1H-benzo[d]imidazol-2-yl)aniline (ANP) and N-(pyren-1-ylmethylene)-2-(1H-benzo[d]imidazol-2-yl)-aniline (PYP) exhibited high selectivity and sensitivity towards Al3+ ion over other interfering and competing cations in aqueous solution. Job's plot analysis reveals that the interaction of ANP/PYP with Al3+ was 1:1 binding stoichiometry. The detection limit of probes ANP and PYP for Al3+ ions were found to be 1.85 x 10(-7) M and 1.08 x 10(-7) M, respectively. The DFT/TD-DFT calculations have also been revealed that the ICT mechanism is responsible for the observed photophysical changes. Moreover, the probes ANP and PYP were applicable to image intracellular Al3+ ions in living cells via confocal fluorescence microscopy technique.