A ratiometric turn-on chemosensor for highly selective and sensitive visual detection of Zn2+ and its applications to environmental samples

A new chemosensor (2-hydroxy-5-methyl-1,3-phenylene)bis(methaneylylidene)) dipicolinohydrazonamide (DP) has been successfully developed, which exhibits a specific selectivity by detecting Zn2+ ions in IPA/water solutions. The receptor DP demonstrates a rapid increase in fluorescence upon detection of Zn2+ without interference from other ions. A substantial fluorescence enhancement was noticed after the addition of Zn2+ ions. Receptor DP has excellent selectivity and sensitivity towards Zn2+ ions over the other metal ions in a semi-aqueous medium, with a low detection limit of 24 mu M. In addition, the fluorescence sensing mechanism is further examined using the job's plot and ESI-MS spectra. Moreover, the density functional theory (DFT) simulations are used to determine the optimal geometries of DP and its complexity, resulting in enhancing our comprehension of the sensing mechanism. Significantly, the non-toxic DP may effectively serve as a visual tool for accurately detecting the presence of Zn2+ in SBG cells, test strips, and water samples, which could have important implications for its possible use in biology and the environment.