A novel pyrene-based aggregation induced enhanced emission active Schiff base fluorophore as a selective “turn-on” sensor for Sn2+ ions and its application in lung adenocarcinoma cells

•1-Aminopyrene and 5-bromo-2-thiophene carboxaldehyde based Schiff base PY-SB was synthesized.•The AIEE (Aggregation Induced enhanced emission) PY-SB showed 24 folds enhancement in fluorescence intensity in tetrahydrofuran (THF) and water mixtures (50:50).•PY-SB was found to be a highly selective and sensitive tool for the “turn-on” detection of Sn2+ ion with the detection limit of 1.63 µM.•The complexation stoichiometry was found to be 2:1 (Sn2+:PY-SB), which was further confirmed by DFT analysis.•In vitro studies on lung adenocarcinoma cells were successfully carried out.