A new fluorogenic probe for solution and intra-cellular sensing of trivalent cations in model human cells

A new imidazole functionalized anthracene based Schiff base (L) was synthesized and itʹs selective colorimetric as well as fluorescence responses to trivalent metal cations (Al3+, Fe3+ and Cr3+) over a variety of divalent and monovalent metal cations in 1:1 methanol–water mixed solvent and in live HeLa cells were demonstrated. These selective colorimetric and fluorescence responses were explained as a consequence of protonation of L, where the lower Ksp values of M3+ (Al3+, Fe3+ and Cr3+) facilitated the generation of H+ through hydrolysis. This fluorogenic behavior of the ligand L was further confirmed by theoretical calculations.