Amperometric determination of sulfide ion by glassy carbon electrode modified with multiwall carbon nanotubes and copper (II) phenanthroline complex

作者：Shamsipur Mojtaba^*; Roushani Mahmoud; Pourmortazavi Seied M; Shahabadi Nahid

来源：CENTRAL EUROPEAN JOURNAL OF CHEMISTRY, 2014, 12(10): 1091-1099.

DOI：10.2478/s11532-014-0552-0

• Cu(II)-complex
• Multi-wall carbon nanotubes
• Glassy carbon modified electrode
• Sulfide ion
• Electrocatalysis

Electrocatalytic oxidation of sulfide ion on a glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNTs) and a copper (II) complex was investigated. The Cu(II) complex was used due to the reversibility of the Cu(II)/Cu(III) redox couple. The MWCNTs are evaluated as a transducer, stabilizer and immobilization matrix for the construction of amperometric sensor based on Cu(II) complex adsorbed on MWCNTs immobilized on the surface of GCE. The modified GCE was applied to the selective amperometric detection of sulfide at a potential of 0.47 V (vs. Ag/AgCl) at pH 8.0. The calibration graph was linear in the concentration range of 5 A mu M-400 A mu M; while the limit of detection was 1.2 A mu M, the sensitivity was 34 nA A mu M-1. The interference effects of SO3 (2-), SO4 (2-), S2O3 (2-), S4O6 (2-), Cysteine, and Cystein were negligible at the concentration ratios more than 40 times. The modified electrode is more stable with time and more easily restorable than unmodified electrode surface. Also, modified electrode permits detection of sulfide ion by its oxidation at lower anodic potentials.

• 出版日期2014-10