Synthesis of Novel Optical Chemosensors for Solvatochromic Behavior, Metal Ions Recognition and Anticancer Applications.

In this study, we synthesized three novel optical chemosensors namely; 3-((5-Chloro-2-hydroxyphenyl) diazenyl)-2-methylquinazolin-4(3H)-one (Chemosensor 1), 2-((5-Chloro-2-hydroxyphenyl)diazenyl) benzophenone (Chemosensor 2), and 5-(3-(1H-pyrrol-2-yl)acryloyl)-4-(4-(dimethylamino)phenyl)-6-methyl-3,4-dihydropyrimidin-2(1H)-one (Chemosensor 3). These chemosensors were structurally confirmed using elemental analysis, FT-IR, H=-NMR, C-NMR, and mass spectrometry (MS). The solvatochromic behavior of the chemosensors was systematically investigated in solvents of varying polarities to identify the dominant fluorescent tautomeric form and assess their photophysical properties. Parameters such as absorption maxima, emission behavior, and fluorescence quantum yield were measured. To evaluate their optical and colorimetric sensing capabilities, the chemosensors were tested against various metal ions like Mn, Fe, Co, Ni, Zn and Pb using naked-eye detection, as well as UV-Visible absorption and fluorescence spectroscopy. Chemosensors exhibited high selectivity and sensitivity toward specific metal ions, demonstrating their potential as efficient metal ion probes. Moreover, binding constants and stoichiometry of the chemosensor-metal complexes were determined using the Benesi-Hildebrand approach and Job's method, respectively. These analyses confirmed the formation of stable sensor-metal ion complexes and provided insight into their molecular interactions. Furthermore, the investigated chemosensors exert an antineoplastic impact against different cancerous cells including PC-3, HCT-116, HepG2, and MCF-7. Importantly, chemosensor 3 exhibited superior cytotoxic effect against all investigated cancer types compared to chemosensor 1 and 2. The cytotoxic impact was confirmed by molecular docking analysis which indicated that chemosensors could have capability to inhibit cyclooxygenase -2 which implicated in many cancers. These findings highlight the multifunctional nature of the synthesized chemosensors, suggesting their potential applicability not only in metal ion sensing but also in anticancer research.