A cyanobiphenyl–based fluorescent ''lighting–up'' sensor for highly selective and sensitive recognition of Al3+: Theoretical, practical and bioimaging studies

[Display omitted] •A novel cyanobiphenyl–based fluorogenic ''lighting up'' probe CATH for Al3+ was developed.•The CATH has an ultralow detection limit (13.1 nM).•Theoretical studies were strongly confirmed the spectral data.•The CATH was used to recognize Al3+ in water, fish samples and living cells. The recognition of toxic Al3+ in foods and biosystems has of great interest to researchers. Herein, a novel cyanobiphenyl–based chemosensor CATH (E)-N'-((4′-cyano-4-hydroxy-[1,1′-biphenyl]-3-yl)methylene)thiophene-2-carbohydrazide was fabricated and shown to recognize Al3+ in HEPES buffer:EtOH (90:10, v:v, pH = 7.4) by ''lighting–up'' fluorescence sensing. The CATH evidenced high sensitivity (LOD = 13.1 nM) and excellent selectivity to Al3+ over competing cations. The Job's plot, TOF–MS and theoretical computation studies were performed to probe the binding mechanism of Al3+ to CATH. Additionally; CATH was successfully utilized to practical applications and employed to recover of Al3+ from different food samples. More importantly, it was employed to intracellular Al3+ detection in living cells including THLE2 and HepG2.