Two Rival Newly Fabricated Potentiometric Sensors to Enhance Selectivity Toward Cu(II) Ions

Abstract

Utilizing the well-known ability of Schiff base ligands to bind metal ions, two newly fabricated ligands, namely: 2-((2-hydroxybenzylidene)amino)benzoic acid (L1) and 2-(furan-2-ylmethyleneamino)phenol (L2) were employed to coordinate copper(II) (Cu(II)) producing the characteristically stable complexes that performed as the ionophores in the presently fabricated electrodes A and B. Thus it was possible to build these electrodes that have attractive properties and expected behavior, namely, low detection limits: 2.32 × 10–7 and 1.14 × 10–6 M Cu(II), Nernstian slope of 29.13 and 30.85 mV/decade Cu(II), broad concentration ranges from 3.98 × 10–7–1.00 × 10–2 and 1.52 × 10–6–1.00 × 10–2 M for sensors A and B, respectively, as well as short response time (ca. 3– 5 s) with distinct selectivity toward Cu(II) over the other cations and applicability over the pH range 1.5–5.5 for miscellaneous samples: aqueous solutions, urine, and blood serum. Thus, these sensors surpass many others towards fulfilling the intended function of Cu(II) determination in various applications.