A cell-compatible phenolphthalein-aminophenol scaffold for Al3+ sensing assisted by CHEF phenomenon

Abstract

Monitoring of excess Al3+ and its selective detection in biological and environmental samples are important tasks for researcher due to its harmful effects. Herein, we present a phenolphthalein-aminophenol derived sensor (PFAP) for the selective fluorescent response of Al3+ in an "OFF-ON" mode over a pool of analytes including eighteen cations with striking greenish emission. It has a prominent limit of detection (LOD) value (1.5 mu M), fast response time (10 s) for Al3+ detection. The complexation properties of PFAP with Al3+ ions were clarified by UV-vis, H-1 & C-13 NMR, HRMS, and FTIR spectroscopic experiments. The recognition mechanism of PFAP for Al3+ working with chelation enhanced fluorescence (CHEF) and is verified with two model compounds PF and PFAN in the light of UV-vis, PL, TRPL, and NMR experiment. To check its applicability, easily prepared test paper and TLC strip of PFAP was produced for rapid and selective onsite detection of Al3+ ions. Bio-imaging application of PFAP in human lung cancer cell lines A549 demonstrated excellent results with negligible cytotoxicity and as an excellent marker to detect traces of Al3+ ion in a time-dependent as well as concentration-dependent manner. Actual sample analysis for Al3+ with the probe PFAP produces fruitful result. (c) 2021 Elsevier B.V. All rights reserved.