Approaches for multicopper oxidases in the design of electrochemical sensors for analytical applications

Author(s)

Matos, Iorquirene O. ^{[1, 2]} ; Ferreira, Tiago L. ^[3] ; Paixao, Thiago R. L. C. ^[1] ; Lima, Alex. S. ^[4] ; Bertotti, Mauro ^[4] ; Alves, Wendel A. ^{[1, 2]}

Affiliation

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre, SP - Brazil

^[2] Inst Nacl Ciencia & Tecnol Bioanalitica, BR-13083970 Campinas, SP - Brazil

^[3] Univ Fed Sao Paulo, Sao Paulo, SP - Brazil

^[4] Univ Sao Paulo, Inst Quim, Sao Paulo - Brazil

• Document type: Journal article
• Source: Electrochimica Acta; v. 55, n. 18, p. 5223-5229, JUL 15 2010.
• Web of Science Citations: 10

Abstract

We report an effective approach for the construction of a biomimetic sensor of multicopper oxidases by immobilizing a cyclic-tetrameric copper(II) species, containing the ligand (4-imidazolyl)ethylene-2-amino-1-ethylpyridine (apyhist), in the Nafion (R) membrane on a vitreous carbon electrode surface. This complex provides a tetranuclear arrangement of copper ions that allows an effective reduction of oxygen to water, in a catalytic cycle involving four electrons. The electrochemical reduction of oxygen was studied at pH 9.0 buffer solution by using cyclic voltammetry, chronoamperometry, rotating disk electrode voltammetry and scanning electrochemical microscopy techniques. The mediator shows good electrocatalytic ability for the reduction of O(2) at pH 9.0, with reduction of overpotential (350 mV) and increased current response in comparison with results obtained with a bare glassy carbon electrode. The heterogeneous rate constant (k(ME)') for the reduction of O(2) at the modified electrode was determined by using a Koutecky-Levich plot. In addition, the charge transport rate through the coating and the apparent diffusion coefficient of O(2) into the modifier film were also evaluated. The overall process was found to be governed by the charge transport through the coating, occurring at the interface or at a finite layer at the electrode/coating interface. The proposed study opens up the way for the development of bioelectronic devices based on molecular recognition and self-organization. (C) 2010 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 08/57805-2 - Institute of Bioanalytics
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 09/07859-1 - Development of voltammetric electronic tongues towards the characterization and identification of adulteration and falsification processes of biofuels
• Grantee: Thiago Regis Longo Cesar da Paixão
• Support Opportunities: Regular Research Grants