Impedance spectroscopy and conductometric biosensing for probing catalase reaction with cyanide as ligand and inhibitor

Abstract : In this work, a new biosensor was prepared through immobilization of bovine liver catalase in a photoreticulated poly (vinyl alcohol) membrane at the surface of a conductometric transducer. This biosensor was used to study the kinetics of catalase-H202 reaction and its inhibition by cyanide. Immobilized catalase exhibited a Michaelis-Menten behaviour at low H202 concentrations (< 100 mM) with apparent constant KMapp = 84 ± 3 mM and maximal initial velocity VMapp = 13.4 μS min− 1. Inhibition by cyanide was found to be non-competitive and inhibition binding constant Ki was 13.9 ± 0.3 μM. The decrease of the biosensor response by increasing cyanide concentration was linear up to 50 μM, with a cyanide detection limit of 6 μM. In parallel, electrochemical characteristics of the catalase/PVA biomembrane and its interaction with cyanide were studied by cyclic voltammetry and impedance spectroscopy. Addition of the biomembrane onto the gold electrodes induced a significant increase of the interfacial polarization resistance RP. On the contrary, cyanide binding resulted in a decrease of Rp proportional to KCN concentration in the 4 to 50 μM range. Inhibition coefficient I50 calculated by this powerful label-free and substrate-free technique (24.3 μM) was in good agreement with that determined from the substrate-dependent conductometric biosensor (24.9 μM).
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Bioelectrochemistry, Elsevier, 2011, 80 (2), pp.155-161. 〈10.1016/j.bioelechem.2010.07.006〉
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https://hal.archives-ouvertes.fr/hal-00703801
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Soumis le : lundi 4 juin 2012 - 13:58:12
Dernière modification le : jeudi 8 février 2018 - 11:10:19

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Naima Bouyahia, Mohamed Larbi Hamlaoui, Mouna Hnaien, Florence Lagarde, Nicole Jaffrezic-Renault. Impedance spectroscopy and conductometric biosensing for probing catalase reaction with cyanide as ligand and inhibitor. Bioelectrochemistry, Elsevier, 2011, 80 (2), pp.155-161. 〈10.1016/j.bioelechem.2010.07.006〉. 〈hal-00703801〉

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