Synthesis, characterization, biological properties and sensor applications of novel rhodanine derivative molecules

In this thesis, the synthesis, characterization, anti-microbial activity and ionophore potential in potentiometric sensors of six different novel rhodanine derivative molecules (4a–d, 5a–b) were investigated. For this purpose, following the characterization of newly synthesized rhodanine derivative molecules by spectroscopic methods (1H–, 13C–NMR and FT–IR), all-solid-state contact PVC membrane potentiometric sensors were prepared. The sensors developed using the newly synthesized rhodanine derivative compounds as ionophores exhibited high selectivity towards copper(II), cadmium(II) and barium(II) ions. The linear working ranges of the developed copper(II)–, cadmium(II)– and barium(II)–selective sensors were determined as 1.0×10-1–1.0×10-5 M, 1.0×10-1–1.0×10-6 M and 1.0×10-1–1.0×10-7 M, respectively. The detection limits of these sensors were calculated as 2.56×10-6 M, 7.66×10-7 M and 9.77×10-8 M, respectively. In addition, the developed copper(II)–, cadmium(II)–, and barium(II)–selective sensors have Nernstian behavior, fast response time, good reproducibility, and wide pH working range. The surface morphologies of the prepared sensors were investigated by SEM/EDX technique. The developed sensors were applied in various environmental water samples, and the results obtained were compared with AAS. According to these data, the two methods were found to be in good agreement with each other, and the developed sensors were able to determine the analyte ions with very high recoveries. Besides, antimicrobial activities of the synthesized molecules were evaluated using the disk diffusion technique, and some of the synthesized molecules were found to have moderate antimicrobial activity. In conclusion, the newly synthesized rhodanine derivative molecules (4a–d, 5a–b) can be used as sensor materials and can considered to be biologically important molecules.