Spectral studies of synthetic symmetric syringaldehyde di-Schiff azine with β-cyclodextrin inclusion complexes as a fluorescent probe for the detection of metal ions

Abstract

In the past few years, organic fluorescent probes play a crucial role in sensor fields due to their magnificent selectivity and detection ability towards various transition metals and alkali ions. Herein, A facile and profitable Schiff-based symmetrical azine derivative of 4,4′ ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene)) bis2,6-methoxyphenyl, dihydrazone or syringaldehyde Azine (SyA) has been synthesized which was rapidly detected dual metal ions (Cu2+ and Pb2+) in different mechanism pathway via Chelation Enhanced Fluorescence Mechanism (CHEF) and Ligand to Metal Charge Transfer (LMCT) approach in optimized physiological conditions under ACN medium. Simultaneously, the interaction mechanism between the SyA and both metals was studied with the help of Benesi-Hildebrand and 1H NMR spectroscopy. Afterward, we prepared the inclusion complex of β-cyclodextrin with SyA (β-CD:SyA) to enhance water solubility and sensing probability. The complex for the observed surprising result was that complexation not only enhanced their properties and detected the new metal ion of Al3+ (may be due to β-CD hydroxyl group interaction with metal ions) without disturbance detection of Cu2+ and Pb2+. The LOD and binding constant values of SyA and β-CD:SyA towards Cu2+, and Al2+ were calculated by absorbance and fluorescence titration profile. From an application point of view, the antibacterial activity and biological activities were evaluated.