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Electrochemical Properties of the Oxo‐Manganese‐Phenanthroline Complex Immobilized on Ion‐Exchange Polymeric Film and Its Application as Biomimetic Sensor for Sulfite Ions
Author(s) -
Machini Wesley B. S.,
Teixeira Marcos F. S.
Publication year - 2014
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201400289
Subject(s) - sulfite , overpotential , cyclic voltammetry , electrochemistry , reaction rate constant , manganese , inorganic chemistry , chemistry , electrocatalyst , ion exchange , kinetics , electrode , ion , analytical chemistry (journal) , organic chemistry , physics , quantum mechanics
A biomimetic sensor containing the oxo‐bridged dinuclear manganese‐phenanthroline complex incorporated into a cation‐exchange polymeric film deposited onto glassy carbon electrode for detection of sulfite was studied. Cyclic voltammetry at the modified electrode in universal buffer showed a two electron oxidation/reduction of the couple Mn IV (μ‐O) 2 Mn IV /Mn III (μ‐O) 2 Mn III . The sensor exhibited electrocatalytic property toward sulfite oxidation with a decrease of the overpotential of 450 mV compared with the glassy carbon electrode. A plot of the anodic current versus the sulfite concentration for potential fixed (+0.15 V vs. SCE) at the sensor was linear in the 4.99×10 −7 to 2.49×10 −6 mol L −1 concentration range and the concentration limit was 1.33×10 −7 mol L −1 . The mediated mechanism was derived by MichaelisMenten kinetics. The calculated kinetics values were MichaelisMenten rate constant= ${K{{{\rm app}\hfill \atop {\rm M}\hfill}}}$ =1.33 µmol L −1 , catalytic rate constant=6.06×10 −3 s −1 and heterogeneous electro‐chemical rate constant=3.61×10 −5 cm s −1 .