Voltammetric behaviour and amperometric sensing of hydrogen peroxide on a carbon paste electrode modified with ternary silver-copper sulfides containing intrinsic silver

• Published in: Monatshefte für Chemie Vol. 151; no. 4; pp. 511 - 524
• Main Authors: Buljac, Maša, Krivić, Denis, Škugor Rončević, Ivana, Vladislavić, Nives, Vukadin, Jela, Buzuk, Marijo
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.04.2020; Springer Nature B.V
• Subjects: Acids; Analytical Chemistry; Carbon; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Citric acid; Contact lenses; Copper; Copper sulfides; Electrical measurement; Electrochemical analysis; Electrodes; Hydrogen peroxide; Inorganic Chemistry; Oleic acid; Organic Chemistry; Original Paper; Physical Chemistry; Reproducibility; Silver chloride; Theoretical and Computational Chemistry; Uric acid; Reduction mechanism; Electrochemistry; Contact lens solution; Sensors; Metals; Modified carbon electrode
• ISSN: 0026-9247; 1434-4475
• DOI: 10.1007/s00706-020-02588-4

The electrochemical behavior of three ternary mixed silver-copper sulfides toward hydrogen peroxide, at various pH values, is presented. Electrochemical characterization, performed using modified carbon paste electrode, revealed that the material that consists of Ag 1.2 CuS 2 , AgCuS, and intrinsic metallic silver showed favorable electrochemical signal in the presence of H 2 O 2 , when measurements were performed at pH 5. According to the results of the additional electrochemical investigation, a novel mechanism involved in the genesis of electroanalytical signal is proposed. Obtained electronalytical signal, at operating potential of the 0 V (vs. Ag/AgCl) toward H 2 O 2 , is proposed to proceeds according to the chemical-electrochemical (CE) mechanism without direct electrochemical reaction of H 2 O 2 at the electrode. The amperometric response is linear in the 1–1000 μM H 2 O 2 concentration range with a detection limit of the 0.055 μM. Sensitivity is calculated to be 16.82 μA cm −2  mM −1 . As optimum pH value, pH 5 was selected. In the presence of the uric acid, asorbic acid, oleic acid, citric acid, and glucose no interference on the amperometric signal was observed. Being a robust and a simple electrode, with remarkable stability, repeatability, and reproducibility, the optimized electrode was successfully tested for determination of the hydrogen peroxide in a commercially available contact lens solution. Graphic abstract