Amperometric Biosensor Based on Galactose Oxidase Immobilized in Clay Matrix.

Franck Charmantray (1) , Nadia Touisni (1) , Laurence Hecquet (1) , Christine Mousty (2)

1 SEESIB - Synthèse et étude de systèmes à intêret biologique
2 MI

An amperometric galactose biosensor was developed by immobilizing galactose oxidase (GAOx) within a laponite clay film coated on a Pt electrode surface. The electrochemical assays were performed by potentiostating the GAOx/laponite bioelectrodes at +0.6 V vs. Ag/AgCl in order to oxidize the enzymatically generated hydrogen peroxide. The bioelectrochemical responses of the biosensors were optimized with regard to the buffer nature, the pH, and the GAOx/laponite ratios. Laponite provides a favorable environment to GAOx activity, since the optimized biosensor GAOx/laponite (50:25; mg:mg) shows a great sensitivity and maximum current (85 mA M 1 cm 2 and 232 mA cm 2, respectively) over a linear galactose concentration range of 1.0 10 6-1.6 10 3 M. It is also stable at least for four weeks at 48C.

Mots clés: Clay; Laponite; Amperometry; Biosensor; Galactose oxidase; Dihydroxyacetone; Galactose

Franck Charmantray, Nadia Touisni, Laurence Hecquet, Christine Mousty. Amperometric Biosensor Based on Galactose Oxidase Immobilized in Clay Matrix.. Electroanalysis, 2013, 25, pp.630-635. ⟨hal-00799835⟩