Coumarin-hydrazone-based fluorescence sensor for Al(III) detection in aqueous solution: DFT calculation and DNA interaction studies

A new 'turn on' fluorescence chemosensor derived from coumarin-based compounds was successfully synthesised. N'-(2-Oxo-2H-chromene-3-carbonyl)isonicotinohydrazide (H2L) was characterised by different spectroscopic techniques such as IR, UV-vis, and NMR spectroscopy. The electronic structures of H2L and Al@HL were calculated using the density functional theory method using Becke’s three parameter Lee-Yang-Parr (B3LYP) exchange functional with the 6-31G+(d,p) basis set. The detection limit of H2L for the Al (III) ion was found to be 2.6 µM, which is low enough to detect micromolar and is below the World Health Organisation guideline for drinking water.