Redox reaction mechanism of cytochrome c at modified gold electrodes

Sagara, Takamasa; Niwa, Katsumi; Sone, Akiko; Hinnen, C.; Niki, Katsumi

doi:10.1021/la00091a042

Cited by 139 publications

(80 citation statements)

References 3 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2, the potential modulation applied across the redox adsorbate is represented by Eac,F and the electric current IF of the faradaic chemical process can be represented electrically through a charge-transfer resistance, Rct, in series with a pseudo-capacitance, Ca. 26 Those electrical components of the faradaic process then form an admittance YF(ω) ≡ I E R j C parts are respectively described by Eqs. (1) and (2):…”

Section: Theorymentioning

confidence: 99%

Electron-Transfer Rate in Potential-Modulated Redox Reactions with Electro-Active Optical Waveguides

Han

Mendes

2017

ANAL. SCI.

View full text Add to dashboard Cite

A novel methodology has been developed to determine electron-transfer rate in electrically driven redox reactions. Based on a widely adopted electrical circuit describing faradaic processes in an electrochemical cell, the approach uses a combination of impedance data from optical and electrical measurements that are simultaneously acquired in a spectroelectrochemical experiment. Once the consistency of our methodology was experimentally corroborated, it was put to practice for investigating electron-transfer rate of cytochrome c adsorbates at very low concentrations on an indium tin oxide electrode by using a highly sensitive, single-mode, electro-active, integrated optical waveguide platform. Different surface densities of redox species on the electrode interface and different ionic strengths in the electrolyte solution were studied. Higher surface densities and higher ionic strengths are shown to slow down the electron-transfer process between the redox molecules and the working electrode.

show abstract

Section: Theorymentioning

confidence: 99%

Electron-Transfer Rate in Potential-Modulated Redox Reactions with Electro-Active Optical Waveguides

Han

Mendes

2017

ANAL. SCI.

View full text Add to dashboard Cite

show abstract

“…These promoters are generally required to avoid adsorption/denaturation (83,102,103) of cytochrome c on the Au surface. However, such an adsorption is concentration dependent so that lowering the cytochrome c solution concentration below the adsorption limit (possible at NEEs thanks to their lower detection limit) can overcome adsorption-related problems.…”

Section: Electroanalysis With Neesmentioning

confidence: 99%

Template Deposition of Metals

Ugo

Moretto

2007

Handbook of Electrochemistry

View full text Add to dashboard Cite

Template synthesis is a relatively simple and easy procedure which has made the fabrication of rather sophisticated nanomaterials accessible to almost any laboratory. Template synthesis requires access to instrumentation capable of metal sputtering and electrochemical deposition. The characterization of the fabricated nanostructures can be done using instrumental techniques including spectrophotometry, voltammetry, optical microscopy, atomic force microscopy, and electronic microscopies (scanning electron microscopy (SEM) and transmission electron microscopy (TEM)).The method is based on the simple but effective idea that the pores of a host material can be used as a template to direct the growth of new materials. Historically, template synthesis was introduced by Possin (1) and refined by Williams and Giordano (2) who prepared different metallic nanowires with widths as small as 10 nm within the pores of etched nuclear damaged tracks in mica. It was further developed by Martin's group (3-5) and followed by others (6) with the number of examples and applications (7) continually increasing. The nanoporous membranes usually employed as templates are alumina or track-etched polymeric membranes which are widely used as ultrafiltration membranes. Recently, metal nanostructures have also been obtained using the pores created by self-assembly in block copolymer structures under the influence of electric fields and high temperatures (8, 9).The first part of this section focuses on the main characteristics and fabrication techniques used for obtaining templating membranes and depositing metal nanostructures by suitable electroless and electrochemical procedures. Methods such as sol-gel (10-12) or chemical vapor deposition (10, 13), which have been used primarily for the template deposition of carbon, oxides, or semiconducting-based materials, will not be considered here in detail. The second part of the section focuses on the electrochemical properties of the fabricated nanomaterials with emphasis on the characteristics and applications of nanoelectrode ensembles (NEEs). Templating membranes 16.2.2

show abstract

“…Among redox proteins, cytochrome c (cyt c) is probably one of the most extensively explored compound due to its key role in the respiratory chain [7][8][9][10][11][12][13] . Cyt c is a water soluble heme protein, with spherical shape and near 3 nm in diameter, which has the function of accepting electrons from cyt c reductase and delivering them to cyt c oxidase in the mitochondrial inner-membrane 14 .…”

Section: Introductionmentioning

confidence: 99%

Direct Electron Transfer to Cytochrome c Induced by a Conducting Polymer

et al. 2017

View full text Add to dashboard Cite

The direct electron transfer (DET) to redox proteins has become a central topic in the development of biotechnological devices. The present work explores the mechanisms of the direct electrochemistry between cytochrome c and a conducting polymer, PEDOT-PSS. This polymer has been electrosynthesized from its monomers in aqueous solution on gold electrodes and its capabilities for DET to cyt c have been examined by electrochemical and spectroelectrochemical methods. The polymer was electrodeposited with controlled thickness and we determined the electron transfer rate constant for cyt c oxidation was about 2 orders of magnitude higher than those obtained at conventional electrodes. Spectroelectrochemical measurements allowed to evaluate the redox state of the polymer as a function of the potential and, in addition, the observation of intrinsic cyt c redox activity upon electron transfer from the conducting polymer. During the oxidation process of this protein, lysine residues placed near the heme crevice interact electrostatically with the anionic polyelectrolyte PSS. This interaction favors the orientation of the heme group towards the chains of PEDOT backbone, which is the eventual responsible for the electron transfer to the protein.3

show abstract

Redox reaction mechanism of cytochrome c at modified gold electrodes

Cited by 139 publications

References 3 publications

Electron-Transfer Rate in Potential-Modulated Redox Reactions with Electro-Active Optical Waveguides

Electron-Transfer Rate in Potential-Modulated Redox Reactions with Electro-Active Optical Waveguides

Template Deposition of Metals

Direct Electron Transfer to Cytochrome c Induced by a Conducting Polymer

Contact Info

Product

Resources

About