Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer

Myoglobin was immobilized with poly(methyl methacrylate)-block-poly[(2-dimethylamino)ethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT). Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transf...

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Main Authors: Carla N. Toledo, Fábio H. Florenzano, José M. Schneedorf
Format: Article
Language:English
Published: Wiley 2014-01-01
Series:International Journal of Electrochemistry
Online Access:http://dx.doi.org/10.1155/2014/184206
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author Carla N. Toledo
Fábio H. Florenzano
José M. Schneedorf
author_facet Carla N. Toledo
Fábio H. Florenzano
José M. Schneedorf
author_sort Carla N. Toledo
collection DOAJ
description Myoglobin was immobilized with poly(methyl methacrylate)-block-poly[(2-dimethylamino)ethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT). Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant (Ks) and transfer coefficient (α) were 0.055±0.01·s−1 and 0.81±0.08, respectively. The reduction potential determined as a function of temperature (293–328 K) revealed a value of reaction center entropy of ΔS0 of 351.3±0.0002 J·mol−1·K−1 and enthalpy change of -76.8±0.1 kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of 114.7±58.7 μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors.
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institution Kabale University
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series International Journal of Electrochemistry
spelling doaj-art-0d84b6adb3e549d4b0206e474591776e2025-08-20T03:54:20ZengWileyInternational Journal of Electrochemistry2090-35292090-35372014-01-01201410.1155/2014/184206184206Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA PolymerCarla N. Toledo0Fábio H. Florenzano1José M. Schneedorf2Biochemistry Laboratory, Federal University of Alfenas, R. Gabriel Monteiro da Silva, 700 Centro, 37130-000 Alfenas, MG, BrazilEngineering School of Lorena, University of São Paulo, Estrada Municipal do Campinho, 12602810 Lorena, SP, BrazilBiochemistry Laboratory, Federal University of Alfenas, R. Gabriel Monteiro da Silva, 700 Centro, 37130-000 Alfenas, MG, BrazilMyoglobin was immobilized with poly(methyl methacrylate)-block-poly[(2-dimethylamino)ethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT). Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant (Ks) and transfer coefficient (α) were 0.055±0.01·s−1 and 0.81±0.08, respectively. The reduction potential determined as a function of temperature (293–328 K) revealed a value of reaction center entropy of ΔS0 of 351.3±0.0002 J·mol−1·K−1 and enthalpy change of -76.8±0.1 kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of 114.7±58.7 μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors.http://dx.doi.org/10.1155/2014/184206
spellingShingle Carla N. Toledo
Fábio H. Florenzano
José M. Schneedorf
Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
International Journal of Electrochemistry
title Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
title_full Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
title_fullStr Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
title_full_unstemmed Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
title_short Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer
title_sort electron transfer of myoglobin immobilized in au electrodes modified with a raft pmma block pdmaema polymer
url http://dx.doi.org/10.1155/2014/184206
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AT fabiohflorenzano electrontransferofmyoglobinimmobilizedinauelectrodesmodifiedwitharaftpmmablockpdmaemapolymer
AT josemschneedorf electrontransferofmyoglobinimmobilizedinauelectrodesmodifiedwitharaftpmmablockpdmaemapolymer