Electrochemical Comparative Study of Riboflavin, FMN and FAD Immobilized on the Silica Gel Modified with Zirconium Oxide

Yamashita, Miyuki; Rosatto, Simone S.; Kubota, Lauro T.

doi:10.1590/s0103-50532002000500015

Cited by 43 publications

(22 citation statements)

References 26 publications

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“…This value is in close agreement with literature values obtained on other electrode surfaces [25] [26]. Fig.…”

Section: Fad Adsorption Thermodynamicssupporting

confidence: 93%

“…Lin and Chen [6] obtained a value of 59 mV/pH for FAD adsorbed on a ZmOmodified GCE. A lower value, 50 mV/pH, was obtained by Yamashita et al [25] for the adsorption of FAD on silica gel modified with ZrO, while Garjonyte et al [26] obtained a value of 52 mV/pH for the adsorption of FAD on Ti in various buffer solutions. On the other hand, Verhagen and Hagen [27] have reported a slope of 59 mV/pH only at pH values below 6.3, while, in the more alkaline environment, the measured value was 32 mV/pH.…”

Section: Fad Adsorption Thermodynamicsmentioning

confidence: 83%

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Interaction of Flavin Adenine Dinucleotide (FAD) with a Glassy Carbon Electrode Surface

Wei

Omanovic

2008

Chemistry & Biodiversity

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The interaction of flavin adenine dinucleotide (FAD) with a glassy carbon electrode (GCE) surface was investigated in terms of the FAD adsorption thermodynamics and kinetics, the subsequent electroreduction mechanism, and the corresponding electron-transfer rate. The kinetics of FAD electroreduction at the GCE was found to be an adsorption-controlled process. A set of electroreduction kinetic parameters was calculated: the true number of electrons involved in the FAD reduction, n=1.76, the apparent transfer coefficient, alpha(app)=0.41, and the apparent heterogeneous electron-transfer rate constant, k(app)=1.4 s(-1). The deviation of the number of exchanged electrons from the theoretical value for the complete reduction of FAD to FADH(2) (n=2) indicates that a small portion of FAD goes to a semiquinone state during the redox process. The FAD adsorption was well described by the Langmuir adsorption isotherm. The large negative apparent Gibbs energy of adsorption (DeltaG(ads)=-39.7 +/-0.4 kJ mol(-1)) indicated a highly spontaneous and strong adsorption of FAD on the GCE. The energetics of the adsorption process was found to be independent of the electrode surface charge in the electrochemical double-layer region. The kinetics of FAD adsorption was modeled using a pseudo-first-order kinetic model.

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“…This value is in close agreement with literature values obtained on other electrode surfaces [25] [26]. Fig.…”

Section: Fad Adsorption Thermodynamicssupporting

confidence: 93%

Section: Fad Adsorption Thermodynamicsmentioning

confidence: 83%

Interaction of Flavin Adenine Dinucleotide (FAD) with a Glassy Carbon Electrode Surface

Wei

Omanovic

2008

Chemistry & Biodiversity

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“…Other possible causes are the resistance of the material or an electron transfer process occurring by an electro-hopping mechanism [34,35]. Figure 4 shows the cyclic voltammetric effects of different GTP concentrations in a haemoglobin solution using a studied the effect of ATP on haemoglobin.…”

Section: Dependence Of Peak Current On the Scan Ratementioning

confidence: 99%

Use of silver nanoparticles as an electron transfer facilitator in electrochemical ligand-binding of haemoglobin

et al. 2007

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Silver nanoparticles have an activity for high intensity electron transfer. They can facilitate the electron transfer from the redox centre of a protein, as a high volume molecule, to the electrode surface. In this study, silver nanoparticles were deposited on the surface of a graphite carbon electrode in the 1 V potential region. Deposition of silver nanoparticles, with a diameter between 70 and 150 nm, was observed on the graphite electrode by transmission electron microscopy (TEM). The results demonstrated that the fine redox waves of haemoglobin could be achieved after modification of the graphite electrode by silver nanoparticles. The cathodic and anodic peaks of haemoglobin were at -135 and +375 mV vs. Ag/AgCl, respectively. The effect of guanosine 3¢,5¢-triphosphate (GTP), guanosine diphosphate (GDP) and guanosine monophosphate (GMP) on the structure of haemoglobin was investigated. It was observed that GTP shifts the cathodic and anodic peaks positively, indicating the transfer of the haem group to the surface of protein as a reflex of easier oxidation and reduction, while GDP and GMP do not show this behaviour. GTP binds with haemoglobin, while GDP and GMP do not.

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“…In order to minimize contributions from interference species during the indirect electrochemical detection of lactate, several approaches have been presented in the literature, including a) modification of electrode by catalyzers such as Prussian blue [32] or cobalt phthalocyanine [33]; b) coimmobilization of horseradish peroxidase (HRP) with LOx [34,35] and c) substitution of the natural acceptor of electrons (O 2 ) by artificial mediators such as methylene green [36], hydroxymethylferrocene [37], redox polymers based on osmium [38] or hydroquinone groups [25]. Different electrode materials have been used such as different carbons, gold and platinum [39][40][41]. Because their surfaces are easily renewed and present low background current and a wide range of working potentials, carbon paste electrodes are the most used [42].…”

Section: Introductionmentioning

confidence: 99%

Development of a Carbon Paste Electrode for Lactate Detection Based on Meldola’s Blue Adsorbed on Silica Gel Modified with Niobium Oxide and Lactate Oxidase

et al. 2011

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A reagentless amperometric biosensor sensitive to lactate was developed. The sensor employs a carbon paste electrode modified with lactate oxidase (LOx) and Meldolas Blue (MB) adsorbed on silica gel coated with niobium oxide. The dependence on the biosensor response was investigated in terms of pH, supporting electrolyte, ionic strength, lactate oxidase (LOx) amounts and applied potential. The biosensor showed an excellent operational stability (96 % of the activity was maintained after 150 determinations) and storage stability (allowing measurements for more than 1.5 months, when stored in a refrigerator). The proposed biosensor also presented good sensitivity allowing lactate quantification at levels down to 6.5 10 À7 mol L À1. Moreover, the biosensor showed a good linear response range (from 0.1 to 5.0 mmol L À1 for lactate). Lactate analysis in biological samples such as blood was also performed. The precision of the data obtained by the proposed biosensor showed reliable results for real complex matrices.

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Electrochemical Comparative Study of Riboflavin, FMN and FAD Immobilized on the Silica Gel Modified with Zirconium Oxide

Cited by 43 publications

References 26 publications

Interaction of Flavin Adenine Dinucleotide (FAD) with a Glassy Carbon Electrode Surface

Interaction of Flavin Adenine Dinucleotide (FAD) with a Glassy Carbon Electrode Surface

Use of silver nanoparticles as an electron transfer facilitator in electrochemical ligand-binding of haemoglobin

Development of a Carbon Paste Electrode for Lactate Detection Based on Meldola’s Blue Adsorbed on Silica Gel Modified with Niobium Oxide and Lactate Oxidase

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