A reversible and efficient probe for dual mode recognition of Al and Cu with logic gate behaviour: Crystal structure, theoretical and in-vivo bio-imaging investigations.

This work presents the synthesis, characterization, crystal structure and spectroscopic investigations of isophthalohydrazide based probe. Among various tested metal ions, the probe selectively detects Al and Cu in aqueous ethanol via fluorometric and colorimetric methods, respectively. It displays a fluorescence "turn-on" response with Al and visual colour change from colourless to yellow with Cu. Sensing mechanism is explored with UV-Vis, fluorescence spectroscopy and H NMR titration, and confirmed with computational results. Suppression of CN isomerization and photo-induced electron transfer (PET) along with chelation enhanced fluorescence emission (CHEF) result in "turn-on" fluorescence with Al while ligand to metal charge transfer (LMCT) accounts for visual colour change with Cu. Job's plot and HRMS confirm 1:2 (L:M) stoichiometry. The probe also exhibits efficient reversibility and reproducibility with EDTA which are successfully mimicked with combinatorial logic gate and truth table. Additionally, solid state applications and bio-imaging investigation on gut tissue of Drosophila 3rd instar larvae are performed.