Biopolymers and cell. 2008; 24 (1): 41 - 50

Optimization of enzymatic bioselective elements as components of potentiometric multibiosensor

O. O. Soldatkin, O. A. Nazarenko, O. S. Pavluchenko, O. L. Kukla, V. M. Arkhipova, S. V. Dzyadevych, O. P. Soldatkin, A. V. El’skaya

The investigation presents the development of highly sensitive and selective multibiosensor based both on a number of immobilized enzymes as bioselective elements and the matrix of ion-selective field effect transistors as transducers of biochemical signal into the electric one. To develop bioselective elements of multi-biosensor, such enzymes as acetylcholinesterase, butyrylcholin esterase, urease, glucose oxidase, and three-enzyme system (invertase, mutarotase, glucose oxidase) were used. Obtained bioselective elements were shown to demonstrate high sensitivity to corresponding substrates in direct enzymatic analysis, which lasted 10 min. Dynamic range of substrate determination (0.1 mM–1.5– 10 mM) was shown to depend on enzymatic system and to differ specifically in upper threshold. Current work presents the investigation on the dependence of multibiosensor response on pH, ionic strength, and buffer capacity of the solution; optimal conditions for simultaneous operation of all bioselective elements of the multibiosensor were selected; the data on cross-influence of substrate of all enzymes used were obtained. The developed multi-analyzer was shown to demonstrate sufficient signal reproducibility.

Keywords: multibiosensor, immobilized enzymes, ion-selective field transistors, glucose oxidase, direct substrate analysis, inhibitor analysis.