A sensitive Schiff-base fluorescent chemosensor for the selective detection of Zn²⁺.

A Schiff-base fluorescent probe - N, N(/)-bis(salicylidene) trans 1, 2 - diaminocyclohexane (H 2 L) was synthesized and evaluated as a chemoselective Zn(2+) sensor. Upon treatment with Zn(2+), the complexation of H 2 L with Zn(2+) resulted in a bathochromic shift with a pronounced enhancement in the fluorescence intensity in ethanol solution. Moreover, other common alkali, alkaline earth and transition metal ions failed to induce response or minimal spectral changes. Notably, this chemosensor could distinguish clearly Zn(2+) from Cd(2+). The stoichiometric ratio and association constant were evaluated using Benesi - Hildebrand relation giving 1:1 stoichiometry. This further corroborated 1:1 complex formation based on Job's plot analyses.