Ortho-Vanillin based multifunctional scaffold for selective detection of Al3+and Zn2+employing molecular logic with DFT study and cell imaging with live Grass pea

Ligand (E)-N'-(2-hydroxy-3-methoxybenzylidene) acetohydrazide (HL) has been designed and synthesized from o-vanillin and acetohydrazide for selective sensing of Al3+ and Zn2+ ions. In the photoluminescence studies, the receptor HL itself shows very poor fluorescence but on incremental addition of Al3+ and Zn2+ ions in solution of the probe HL individually leads to a sharp increase in emission intensities at wavelengths 468 nm (-15 fold) and 504 nm (-8 fold) respectively. Due to excited state intramolecular proton transfer (ESIPT), HL exhibits weak emission in absence of any analytes but in presence of Al3+ and Zn2+, chelation-enhanced fluorescence (CHEF) with coordination of Al3+ and Zn2+ inhibits ESIPT, which results large increase of fluorescence enhancement. The ligand HL shows high selectivity and sensitivity to detect Al3+ and Zn2+ among various metal ions with LOD (Limit of Detection) 0.836 x 10-6 M and 1.01 x 10-6 M respectively. DFT calculation has been performed to study the binding phenomenon of ligand HL with metal ions. A molecular logic gate has been build-up with Al3+ and Zn2+ and EDTA as three chemical input. Simultaneously, cytotoxicity and cell biology for the probe and corresponding Al3+ sensing were observed.

Automated summary

The ligand (E)-N'-(2-hydroxy-3-methoxybenzylidene) acetohydrazide (HL) has been synthesized for selective sensing of Al3+ and Zn2+ ions. In the presence of these ions, HL shows a significant increase in fluorescence intensity due to chelation-enhanced fluorescence. HL exhibits high selectivity and sensitivity with LOD of 0.836 x 10-6 M for Al3+ and 1.01 x 10-6 M for Zn2+. DFT calculation is used to study the binding of HL with metal ions. The cytotoxicity and cell biology of the probe and Al3+ sensing are also observed.