Imidazole derived PET based reversible dual fluorescent chemosensor: sensing of zinc and carbonate ions and their usage on real samples and live cells

Three imidazole based chemosensors, HNBI, 1-NBI, and 2-NBI, were designed, synthesized and confirmed using 1H, 13C, and mass spectroscopy methods. All three receptors were tested in the presence of different cations and anions in DMSO-H2O (1:1 v/v, HEPES = 50 mM, pH-7.4) solution, while HNBI, which benefits from the -OH moiety, shown fluorescence increase for Zn2+ and CO32− ions. Through the use of a jobs plot and Benesi-Hildebrand experiments, a 1:1 binding stoichiometry was discovered. The simultaneous LOD and LOQ for the detection of Zn2+ and CO32− were determined to be 1.07 × 10−9 M, 3.57 × 10−9 M, and 9.72 × 10−8 M, 3.24 × 10−9 M, respectively. By using 1H NMR titration, the binding ratio between the host and guest were further verified. Restriction of C-C free rotation and blocking of the Photoinduced Electron Transfer (PET) are the two effects that follow receptor HNBI's interaction with Zn2+/CO32− ions. Additionally, HNBI was successfully examined for the detection of Zn2+/CO32− ions in water, food, soil and bacterial cell lines.