Isoniazid-Sugar–Triazole-Based Fluorescent “Turn-On” Chemosensor for Zn2+ and Mn2+ Detection With Potential Biological Applications

A multifunctional isoniazid-sugar–triazole based Schiff-bases were designed and synthesized, and their sensing capability was studied with various metal ions by colorimetric, absorption, and spectrofluorometric techniques. Interestingly, the molecule processing diethylamine moiety (11) shows fluorescent “turn-on” chemosensor properties in the presence of Zn²⁺ and Mn²⁺. The limit of detection (LOD) values of the chemosensor toward the respective metal ions were 3.37 µM and 1.46 µM, with a 1:2 stoichiometric ratio, respectively. Compound 11 was successfully applied to effectively detect Zn²⁺ and Mn²⁺ in real water samples. Additionally, a logic gate was constructed, where the fluorescence intensity served as the output signal, responding to the chemical species as the inputs. Synthesized compounds were screened for their antibacterial activities against a panel of pathogenic bacteria, such as Staphylococcus aureus, Streptococcus pyogenes, and E. coli. All the compounds showed significant activities against these pathogens. The anticancer activity of compound 13 was investigated in human osteosarcoma (HOS) cells. MTT assay results revealed that the hybrid sugar derivative exhibited cytotoxicity against the HOS cell line, with increased potency observed at a concentration of 60 µg/ml.