Comparative Study of Carbon Paste, Screen Printed, and PVC Potentiometric Sensors Based on Copper-sulphamethazine Schiff Base Complex for Determination of Iodide - Experimental and Theoretical Approaches

摘要

New poly vinyl chloride (PVC) membrane, carbon paste (CP), and screen printed (SP) electrodes are constructed for iodide sensing. They are based on copper (II)-sulphamethazine Schiff base complex as suitable carrier. Mechanism was proved by FT-IR and UV-Vis spectroscopy. Computational study involving binding energies calculations at DFT/B3LYP level of theory confirmed the proposed mechanism and agreed the observed selectivity pattern. Responses are near-Nernstian (-55.0, -51.0 mV/concentration decade) for PVC, and SP electrodes, and super-Nernstian (-61.2 mV/concentration decade) for the CP electrode. Lower limit of detection (3.2x10(-6) mol.L-1) and improved selectivity over the highly interfering thiocyanate were obtained in comparison with the previously reported Schiff base complexes-based iodide sensors.