Highly selective and sensitive benzo-imidazo-pyrrolo[3,4-c] pyridines based chemosensor for iron, DFT calculation and its biological application.

• Benzo-imidazo-pyrrolo[3,4-c] pyridines based fluorescent chemosensor for Fe2+ ion detection. • The chemosensor shows a high selectivity for Fe2+ over other common metal ions. • This chemosensor was successfully applied for imaging Fe2+ion in living hela cells. • The probe can be recycled and reused with good efficiency upto twenty cycles. A new fluorescent chemosensor with benzo-imidazo-pyrrolo[3,4-c] pyridines core was synthesized and characterized. The free chemosensor exhibited high fluorescence intensity with quantum yield (φ) of 0.498. The fluorescence intensity was quenched completely in the presence of iron over other common metal ions at physiological pH. The chemosensor formed 1:1 complex with iron and the quantum yield was determined to be 0.04 for the complex. Quenching mechanism of the chemosensor can be confirmed by various analytical methods such as UV–vis titration, Job plot and mass spectrometry analysis. DFT calculation of the complex was also carried out which confirmed the formation of complex between metal and chemosensor. Further, this chemosensor was applied for in vitro cell imaging in HeLa cells to illustrate that the chemosensor can be used as a fluorescent probe for monitoring Fe2+ in living cells. [Display omitted] [ABSTRACT FROM AUTHOR]