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

• Newly synthesized colorimetric and flourogenic probe can selectively sense trivalent metal ions in mixed aqueous medium in ppm level.
• Theoretical calculations justify the red shift and increase in emission intensity of L in the presence of M3+.
• Interestingly, L alone and L in the presence of different trivalent cations were non-cytotoxic to model human cells (HeLa cells).
• The switch ON emission behaviour of the ligand in the presence of M3+ is also demonstrated inside live HeLa cells.

A new imidazole functionalized anthracene based Schiff base (L) was synthesized and it's 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.

A simple Schiff's base fluorogenic probe for trivalent cation is designed. The receptor is biocompatible and used for live cell imaging.Figure optionsDownload as PowerPoint slide