Electrochemical metal-ion sensor based on a cobalt phthalocyanine complex captured in Nafion® on a glassy carbon electrode

Abstract

This article describes an electrochemical metal-ion sensor based on a cobalt phthalocyanine (CoPc) complex and determination of its sensor activity for some transition metal ions. Ag⁺ and Hg²⁺, among several transition metal ions, coordinate to the sulfur donors of CoPc and alter the electrochemical responses of CoPc in solution, indicating possible application of the complex as Ag⁺ and Hg²⁺ sensor. For practical application, CoPc was encapsulated into a polymeric cation exchange membrane, Nafion, on a glassy carbon electrode and used as an electrochemical coordination element. This composite electrode was potentiometrically optimized and potentiometrically and amperometrically characterized as transition metal-ion sensors with respect to reproducibility, repeatability, stability, selectivity, linear concentration range, and sensitivity. A µmol dm⁻³ sensitivity of the CoPc-based sensor indicates its possible practical application for the determination of Ag⁺ and Hg⁺² in waste water samples.

Keywords:

• Cobalt phthalocyanine
• Nafion
• Electrochemical sensor
• Electrochemistry
• Metal ion

Acknowledgments

This work was supported by the Research Fund of the Marmara University (Project No: FEN-C-YLP-110411-0098).