Electrochemistry, Surface Plasmon Resonance, and Quartz Crystal Microbalance: An Associative Study on Cytochrome c Adsorption on Pyridine Tail-Group Monolayers on Gold

Autor(es)

Paulo, Tercio de F. ^{[1, 2]} ; de Sousa, Ticyano P. ^[2] ; de Abreu, Dieric S. ^[2] ; Felicio, Nathalie H. ^[2] ; Bernhardt, Paul V. ^[3] ; Lopes, Luiz G. de F. ^[2] ; Sousa, Eduardo H. S. ^[2] ; Diogenes, Izaura C. N. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, BR-05508000 Sao Paulo - Brazil

^[2] Univ Fed Ceara, Dept Quim Organ & Inorgan, BR-60455970 Fortaleza, Ceara - Brazil

^[3] Univ Queensland, Sch Chem & Mol Biosci, Brisbane, Qld 4072 - Australia

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry B; v. 117, n. 29, p. 8673-8680, JUL 25 2013.
• Citações Web of Science: 9

Resumo

Quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and electrochemistry techniques were used to study the electron-transfer (ET) reaction of cytochrome c (Cyt c) on gold surfaces modified with thionicotinamide, thioisonicotinamide, 4-mercaptopyridine, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 5-phenyl-1,3,4-oxadiazole-2-thiol, 4,4'-bipyridine, and 4,4'-dithiopyridine. The electro-chemical results showed that the ET process is complex, being chiefly diffusional with steps depending on the orientation of the pyridine or phenyl tail group of the modifiers. The correlation between the electrochemical results and those acquired by SPR and QCM indicated the presence of an adlayer of Cyt c adsorbed on the thiolate SAMs. This adlayer, although being not electroactive, is essential to assess the ET reaction of Cyt c in solution. The results presented in this work are consistent with the statement (Feng Z.Q; Imabayashi, S.; Kakiuchi, T.; Nil, K.J. Electroanal. Chem. 1995, 394, 149-154) that the ET reaction of Cyt c can be explained in terms of the through-bond tunneling mechanism. (AU)

• Processo FAPESP: 11/12479-3 - Monocamadas automontadas de compostos sulfurados: um estudo espectroscópico
• Beneficiário: Tercio de Freitas Paulo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado