Optimization of enzyme bioselective elements as components of potentiometric multibiosensor

Abstract

The investigation presents the development of highly sensitive and selective multibiosensor based on different immobilized enzymes as bioselective elements and the matrix of ion-selective field effect transistors as transducers. To develop bioselective elements of multibiosensor, such enzymes as acetylcholinesterase, butyrylcholin esterase, urease, glucose oxidase, and three-enzyme system (invertase, mutarotase, glucose oxidase) were used. The bioselective elements obtained 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 an enzymatic system and differ specifically in the upper detection limit. The dependence of multibiosensor response on pH, ionic strength, and buffer capacity was investigated; optimal conditions for simultaneous operation of all bioselective elements of the multibiosensor were selected; the data on cross-influence of substrates for all the enzymes used were obtained. The developed multi-analyzer was shown to demonstrate sufficient signal reproducibility.