Monitoring of Biotechnological Processes by Enzyme Electrodes Modified with Carbon Nanotubes

Abstract

The characteristics of biosensors based on screen-printed electrodes containing glucose oxidase, alcohol oxidase, lactate oxidase, and a mixture of glucose oxidase and γ-amylase are studied. The enzymes have been immobilized in a conductive hydrogel of cross-linked bovine serum albumin modified with carbon nanotubes. The developed biosensors are applicable for the quantification of glucose, ethanol, lactic acid, and starch in fermentation media. The analytical and metrological characteristics of these biosensors are determined. The developed biosensor system allows for quantification of glucose, ethanol, lactate, and starch in the concentration range of 0.1–2.7, 1–27, 0.02–73 mM, and 0.6–21 g/L, respectively. Samples of alcoholic and fermented milk products, kvass, and fermentation mass have been analyzed. Statistical analysis of the assay results shows that glucose, ethanol, lactic acid, and starch concentrations determined by biosensors insignificantly differ from those determined by the reference methods. The developed set of biosensors based on specifically selected enzymes can be used for effective monitoring of biotechnological processes as an alternative to the conventional analytical methods.