Synthesis and Characterization of Novel Organic Ionophores: Application as Selective Electrochemical Sensors

Abstract

Carbon ceramic sensor was fabricated using Silica-graphite (SiO2/C). Copper oxide (CuO) was immobilized in situ on (SiO2/C) matrix. SiO2/C/CuO was modified with benzimidazolium-1-acetate ionic liquid by ultra-sonication. Imidazole group present in ionic liquid acts as ionophore. Surface area (SBET = 99.87 m2/g) and pore volume (0.3104 cm³/g) of the material was calculated from BET analyzer. Scanning electron microscopy (SEM) images showed material’s compactness having no phase segregation within the magnification used. These materials were used in the fabrication of working electrodes i.e. SiO2/C, SiO2/C/CuO, SiO2/C/CuO/IL for the selective electrochemical determination of catechol (analyte). Secondly CP/Cu/FA, chemically modified carbon paste electrode was prepared using copper formamidine complex [Cu/FA] because formamidine also behaves as ionophore in the selective electrochemical determination of different analytes. Electrochemical impedance spectroscopy has revealed that the SiO2/C/CuO/IL sensor assists the transfer of charge because of its ionic nature. SiO2/C/CuO/IL electrode exhibits excellent sensitivity, linear response range and low limit of detection (LOD) which are 0.678 nA dm3 µmol-1 cm-2, 0.2 mM – 10 mM and 6.76 x 10-6 mol dm-3 respectively, as compared to other sensor CP/Cu/FA. The sensor also shows very good sensitivity for the determination of catechol in environmental samples taken from Monnoo Yarn Dyeing industry.