A reversible and efficient probe for dual mode recognition of Al3+ and Cu2+ with logic gate behaviour: Crystal structure, theoretical and in-vivo bio-imaging investigations

[Display omitted] •Simple dual mode probe for fluorometric and colorimetric detection of Al3+ and Cu2+.•Characterized by single crystallography, HRMS, NMR, IR and DFT.•Inhibition of PET and CN isomerization are responsible for detection of Al3+.•Reversibility with EDTA is successfully mimicked with combinatorial logic gate.•Bio-imaging application in gut tissue of Drosophila has been efficiently executed. This work presents the synthesis, characterization, crystal structure and spectroscopic investigations of isophthalohydrazide based probe. Among various tested metal ions, the probe selectively detects Al3+ and Cu2+ in aqueous ethanol via fluorometric and colorimetric methods, respectively. It displays a fluorescence “turn-on” response with Al3+ and visual colour change from colourless to yellow with Cu2+. Sensing mechanism is explored with UV–Vis, fluorescence spectroscopy and 1H 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 Al3+ while ligand to metal charge transfer (LMCT) accounts for visual colour change with Cu2+. 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.