Direct electron transfer in immobilized flavoenzyme chemically modified graphite electrodes

Ianniello, Robert M.; Lindsay, Thomas J.; Yacynych, Alexander M.

doi:10.1016/s0003-2670(01)95307-3

Cited by 21 publications

(3 citation statements)

References 22 publications

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“…For this purpose, the bioelectrode prepared by incubation in chitosan solution was submitted to a treatment with concentrated KCl solutions to assess the enzyme denaturation process. It has been reported that treatment with concentrated salt solutions can strip FAD from flavoenzymes, but the same treatment is ineffective in removing adsorbed FAD from graphite surfaces [41][42][43]. Thus, if the specie adsorbed on the graphite surface is the whole GOx enzyme with its protein embedding structure, basic treatment will strip it from the electrode surface and the corresponding redox peaks will disappear from the cyclic voltammogram.…”

Section: Bioelectrode Modification With Glucose Oxidasementioning

confidence: 99%

Low-Denaturazing Glucose Oxidase Immobilization onto Graphite Electrodes by Incubation in Chitosan Solutions

et al. 2022

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In this work, glucose oxidase (GOx) has been immobilized onto graphite rod electrodes through an assisted-chitosan adsorption reaching an enzyme coverage of 4 nmol/cm2. The direct and irreversible single adsorption of the Flavine Adenine Dinucleotide (FAD) cofactor has been minimized by electrode incubation in a chitosan (CH) solution containing the enzyme GOx. Chitosan keeps the enzyme structure and conformation due to electrostatic interactions preventing FAD dissociation from the protein envelope. Using chitosan, both the redox cofactor FAD and the protein envelope remain in the active form as demonstrated by the electrochemistry studies and the enzymatic activity in the electrochemical oxidation of glucose up to a concentration of 20 mM. The application of the modified electrodes for energy harvesting delivered a power density of 119 µW/cm2 with a cell voltage of 0.3 V. Thus, chitosan presents a stabilizing effect for the enzyme conformation promoted by the confinement effect in the chitosan solution by electrostatic interactions. Additionally, it facilitated the electron transfer from the enzyme to the electrode due to the presence of embedded chitosan in the enzyme structure acting as an electrical wiring between the electrode and the enzyme (electron transfer rate constant 2.2 s−1). This method involves advantages compared with previously reported chitosan immobilization methods, not only due to good stability of the enzyme, but also to the simplicity of the procedure that can be carried out even for not qualified technicians which enable their easy implementation in industry.

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Section: Bioelectrode Modification With Glucose Oxidasementioning

confidence: 99%

Low-Denaturazing Glucose Oxidase Immobilization onto Graphite Electrodes by Incubation in Chitosan Solutions

et al. 2022

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“…A series of articles has appeared on amperometric biosensors for amino acids based on a variety of detection principles, e.g., for L-amino acids with hydrogen peroxide detection [26][27][28], with oxygen detection [29][30][31], with ferrocene derivatives [321 as artificial electron acceptor facilitating the electron transfer between the enzyme and the electrode at a less positive .UOD and a less negative potential than the electrochemical reactions for hydrogen peroxide and molecular oxygen, respectively, at tetrathiafulvalene-tetracyanoquinodimethane (TTF TCNQ) conducting salt electrodes [33], direct electron transfer between enzyme and electrode [34], and as mentioned earlier on coimmobilizing HRP with L-MOD [20,21] and for D-amino acids with hydrogen peroxide detection [28], TTF TCNQ electrodes [33], and using an electrode with coimmobilized D-AAOD with HRP and using dimethylferrocene or "TF as a mediator between electrode and HRP [21]. Here we report on reagentless sensors for L-and D-amino acids based on L-or D-MOD coimmobilized with HRP in CPs.…”

Section: Introductionmentioning

confidence: 99%

Amperometric biosensors for detection of L‐ and D‐amino acids based on coimmobilized peroxidase and L‐ and D‐amino acid oxidases in carbon paste electrodes

et al. 1994

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An apparent direct electron transfer between various electrode materials and peroxidases immobilized on the surface of the electrode has been reported in the last few years. An electrocatalytic reduction of hvdrogen peroxide promoted by the immobilized peroxidase starts at about +600 mV (vs. Ag/AgCl) at neutral pH. The efficiency of the electrocatalytic current increases as the applied potential is made more negative and starts to level off at about -100 mV (vs. Ag/AgCl). Amperometric biosensors for hvdrogen peroxide can be constructed with these kinds of peroxidase modified electrodes. By coimmobilizing a hydrogen peroxide-producing oxidase with the peroxidase, amperometric biosensors can be made responding to the substrate of the oxidase within a potential range essentially free of interfering electrochemical reactions. Sensors for L-and D-amino acids are shown based on coimmobilizing HRP with L-amino acid oxidase (L-MOD) or D-amino acid oxidase (D-MOD). The effects of the immobilization procedure, buffer (flow carrier), pH, taken amounts of enzymes, flow rate, and injection volume on the response were investigated. The addition of polvethylenimine (PEI) into the paste was found to increase the response considerably. All 20 of the most common L-amino acids could be detected.

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“…In recent years increasing attention has been paid l -- 15 ) to the electron transfer between an electrode and the active center (or cofactor) of oxidoreductase immobilized on electrode surface. By behaving as a substitute for a chemical elecron acceptor (e.g.…”

mentioning

confidence: 99%

Electrocatalysis with a Glucose-Oxidase-immobilized Graphite Electrode

Ikeda

Katasho

Kamei

et al. 1984

Agricultural and Biological Chemistry

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Direct electron transfer in immobilized flavoenzyme chemically modified graphite electrodes

Cited by 21 publications

References 22 publications

Low-Denaturazing Glucose Oxidase Immobilization onto Graphite Electrodes by Incubation in Chitosan Solutions

Low-Denaturazing Glucose Oxidase Immobilization onto Graphite Electrodes by Incubation in Chitosan Solutions

Amperometric biosensors for detection of L‐ and D‐amino acids based on coimmobilized peroxidase and L‐ and D‐amino acid oxidases in carbon paste electrodes

Electrocatalysis with a Glucose-Oxidase-immobilized Graphite Electrode

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