A simple diaminomaleonitrile based molecular probe for selective detection of Cu(II) and Zn(II) ions in semi-aqueous medium

[Display omitted] •A designed simple schiff base selective towards Cu2+ and Zn2+ ions.•Probe ANTI-DMN effective sense at lower level concentrations 0.204 µM and 2.014 µM.•The interaction of probe with analytes were confirmed with NMR, FTIR, and ESI-MS spectroscopic techniques.•The test kit was developed to monitor real time application for Cu2+ and Zn2+. Diaminomaleonitrile and 4-antipyrene carboxaldehyde based Schiff base probe (ANTI-DMN) was synthesized and it exhibits high sensitivity and selectivity towards Cu2+ and Zn2+ in semi-aqueous medium (CH3CN:H2O, 7:3 v/v). Upon interaction with Cu2+/Zn2+ANTI-DMN showed an instant colour change from colorless to yellow. The sensing ability was further confirmed with various spectroscopic techniques such as UV–Vis, NMR, FT-IR, and ESI-MS. The binding nature of the probe was determined by Job’s plot, from this stoichiometric binding ratio of the probe was calculated to be 1:1 for Cu2+ and Zn2+ ions. The limit of detection of Cu2+ and Zn2+ ions were found to be 0.204 µM and 2.014 µM respectively, which is lesser than the WHO allowed limit in drinking water. The ANTI-DMN coated test kit was developed by using silica supported TLC plates, which provided a quick colorimetric response of Cu2+ and Zn2+ ions. Moreover, the theoretical calculations were performed using the DFT/TD-DFT method. ANTI-DMN proved to be an excellent probe for the rapid colorimetric detection of Cu2+ and Zn2+ ions in a semi-aqueous medium.