FLOURESCENT CHEMOSENSOR FOR Y3+ BASED ON 5-BROMO-7-(CARBOXYMETHOXY)-6- HYDROXY-1-METHYLQUINOLINE-1-IUM-3-SULFONATE IN AQUEOUS SOLUTION

From eugenol, the main component of basil essential oil, the ligand 5-bromo-7-(carboxymethoxy)-6-hydroxy-1-methylquinoline-1-ium-3-sulfonate (MeQBr) and the complex YMeQBr were synthesized. The composition and structure of the complexes were determined by combining the results of IR, EDX, ESI MS, 1H NMR, thermal analysis and single crystal X-ray diffraction analysis. The results of the study of the optical properties of the ligand MeQBr and the complex solution YMeQBr showed that at a wavelength of 350 nm, the aqueous solution of MeQBr and its complex had the ability to emit fluorescence. Fluorescence intensity of complex solution of YMeQBr increases 8 times higher than ligand solution in the same concentration. The interaction between MeQBr and some metal ions in aqueous solutions was studied by fluorescence spectroscopy, in various conditions of pH and molar ratio. The results showed that addition of Y3+ ions elicits a significant enhancement of the fluorescence intensity of MeQBr solutions. 10 μM MeQBr solution can be used as a chemical sensor to detect and quantify Y3+ ion in aqueous solution, at pH = 4 - 5 and is not affected by the presence of other ions. The limit of detection (LOD) of Y3+ ion is 5.87 μM. Positive ion mass spectrum shows the formation of a complex at a molar ratio of 1:1 between MeQBr and Y3+. The photoinduced electron transfer mechanism is considered to operate to enhance fluorescence. The results of the antimicrobial activity test showed that the YMeQBr complex had high activity against Bacillus subtilis and Lactobacillus fermentum strains with low IC50 values of 1.65 and 0.53μg/ml, respectively, and the YMeQBr complex had high activity against Candida albican strain with IC50 = 113.36μg/mL. For citation: Nguyen Thi Ngoc Vinh, Le Thi Hong Hai, Nguyen Thi Ngoc Mai Flourescent chemosensor for Y3+ based on 5-bromo-7-(carboxymethoxy)-6-hydroxy-1-methylquinoline-1-ium-3-sulfonate in aqueous solution. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2026. V. 69. N 3. P. 6-15. DOI: 10.6060/ivkkt.20266903.7274.