An electrochemical method has been developed to determine iodide in urine using an electrode modified with silver oxide microparticles-poly acrylic acid/poly vinyl alcohol (Ag2OMPs-PAA/PVA). Silver oxide particles were formed by electrochemical oxidation via cyclic voltammetry. The modified electrode exhibited an excellent response to iodide detection by cathodic stripping voltammetry. The fabrication and operation conditions were optimized in terms of PVA concentration, K2HPO4 concentration, amount of AgMPs-PAA/PVA, number of cycles for oxide formation, electrolyte, applied potential (vs. Ag/AgCl), and time. Under the optimum conditions, iodide determination produced a linear range from 1 to 40 μM. The limit of detection was 0.3 μM. Precision was found to be within 7.4% RSD. The developed method was applied to the determination of iodide in urine samples of pregnant women with satisfying recoveries (86 ± 1 to 108 ± 1%). Graphical abstract.
Keywords: Cathodic stripping voltammetry; Electrochemical iodide sensor; Pregnant women; Silver oxide microparticles; Urine analysis.