Author(s): Ramanavicius A, Kausaite A, Ramanaviciene A
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Abstract This study describes a new, basic procedure for the tuning of some analytical parameters of enzymatic biosensors that are based on hydrogen peroxide-producing oxido-reductases. An amperometric biosensor based on glucose oxidase (GOx) (EC 188.8.131.52) from Penicillum vitale, immobilized on a carbon rod electrode by cross-linking with glutaraldehyde, was exploited as a model system for demonstration of the approach described here. Such an important analytical parameter as the upper detection limit was dramatically changed by the formation of a polypyrrole conducting polymer layer by the GOx-induced polymerization of polypyrrole (Ppy). An increase in the upper detection limits for differently modified electrodes was estimated by calculation of the apparent Michaelis-Menten constant [K(M(app))]. A significant increase in the long-term stability of the GOx-based electrode modified by Ppy (GOx/Ppy) was detected compared with that of an unmodified one. Further application of this approach, based on the self-encapsulation of glucose oxidase and other oxidases, is predicted for such biosensors where extension of the detection rate as well as K(M(app)) are required.
This article was published in Analyst
and referenced in Journal of Analytical & Bioanalytical Techniques