Reagentless amperometric biosensors highly sensitive to hydrogen peroxide, glucose and lactose based on N-methyl phenazine methosulfate incorporated in a Nafion film as an electron transfer mediator between horseradish peroxidase and an electrode

1997 ◽  
Vol 344 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Haiying Liu ◽  
Tailin Ying ◽  
Kang Sun ◽  
Haihong Li ◽  
Deyao Qi
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Horseradish Peroxidase ◽  
Phenazine Methosulfate ◽  
Amperometric Biosensors ◽  
Electron Transfer Mediator ◽  
Highly Sensitive ◽  
Nafion Film

Titration Study of Guaiarcol Oxidation by Horseradish Peroxidase

1975 ◽  
Vol 53 (6) ◽  
pp. 649-657 ◽  
Author(s):  
Marius Santimone
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Low Temperature ◽  
Horseradish Peroxidase ◽  
Catalytic Amount ◽  
Reaction Scheme ◽  
General Mechanism ◽  
Compound I ◽  
Compound Ii ◽  
Titration Study

Titration of guaiacol by hydrogen peroxide in the presence of a catalytic amount of horseradish peroxidase shows that the reduction of hydrogen peroxide proceeds by the abstraction of two electrons from a guaiacol molecule. In the same way, it can be demonstrated that 0.5 mol of guaiacol can reduce, at low temperature, 1 mol of peroxidase compound I to compound II. Moreover, the reaction between equal amounts of compound I and guaiacol at low temperature produces the native enzyme. A reaction scheme is proposed which postulates that two electrons are transferred from guaiacol to compound I giving ferriperoxidase and oxidized guaiacol with the intermediary formation of compound II. The direct two-electron transfer from guaiacol to compound I without a dismutation of product free radicals must be considered as an exception to the general mechanism involving a single-electron transfer.

Oxidation of 4-tert-Butylcatechol and Dopamine by Hydrogen Peroxide Catalysed by Horseradisch Peroxidase

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
M. García-Moreno ◽  
M. Moreno-Conesa ◽  
J.N. Rodríguez-López ◽  
F. García-Cánovas ◽  
R. Varón
Keyword(s):  
Hydrogen Peroxide ◽  
Electron Transfer ◽  
Horseradish Peroxidase ◽  
Resting State ◽  
Intermediate Compound ◽  
Transfer Reactions ◽  
Single Electron Transfer ◽  
Compound I ◽  
Compound Ii ◽  
Enzyme Intermediate

AbstractThe catalytic cycle of horseradish peroxidase (HRP; donor:hydrogen peroxide oxidoreductase; EC 1.11.1.7) is initiated by a rapid oxidation of it by hydrogen peroxide to give an enzyme intermediate, compound I, which reverts to the resting state via two successive single electron transfer reactions from reducing substrate molecules, the first yielding a second enzyme intermediate, compound II. To investigate the mechanism of action of horseradish peroxidase on catechol substrates we have studied the oxidation of both 4-

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