Химия и химические технологии/5. Фундаментальные проблемы создания новых материалов и технологий

Kamanin S.S., PhD, Arlyapov V.A., PhD

Tula State University, Russia

Mediator-free biosensor based on screen-printed electrodes modified with alcohol oxidase for ethanol determination

It is hard to overrate the role of fermentation process in human life. Fermentation is the decomposition process of organic substances, mainly carbohydrates and starchy materials, into simpler compounds under the action of microorganisms or enzymes isolated from them. Alcohol fermentation is one of the most important types of fermentation, which makes it possible to produce wine, beer, ethyl alcohol, etc. Ethanol content monitoring is an integral part of production process and allows to control the completeness of the fermentation [1].

Gas chromatography is currently used to determine the ethanol content. This method is expensive, requires maintenance by qualified specialists and does not allow continuous monitoring, but there is an alternative to classical analytical methods – it is biosensor, described as analytical device consisting of biological recognition element and signal transducer [2]. The development of biosensors has led to the appearance of sensors based on screen-printed electrodes, which are easy to manufacture and can be easily modified for the needs of a specific analysis [3].

The aim of this work was to develop a biosensor based on printed electrodes modified with single-walled carbon nanotubes (SWCNT) and immobilized alcohol oxidase (AO) for determination of low ethanol concentrations. In this work, graphite screen-printed electrodes (Rusens Ltd, Russia) were modified by applying a biocatalyst to the surface of the working electrode. The analytical signal was recorded using the EmStat potentiostat (PalmSens, The Netherlands) integrated with a personal computer.

To impart selectivity to the sensor, a suspension of SWCNT was first applied to the surface of the working electrode, then an aqueous solution of AO was applied, and, finally, the electrode surface was coated with a gel of cross-linked bovine serum albumin (BSA). The main analytical characteristics of the biosensor based on the obtained modified electrodes were determined. On the linear section of the calibration curve the sensitivity was 17 μA·M^-1, the detection range of ethanol concentrations was 1-27 mM.

Using the developed biosensor, the ethanol content in the wine samples was determined. Gas chromatography was used as the reference method. The measurement results coincide within the confidence intervals. From this it follows that the developed mediator-free biosensor based on screen-printed electrodes can be used to analyze samples of fermentation products.

The work was supported by Grant of the RFBR and the Government of the Tula region No. 16-48-710959 р_а (contract ДС/44) and Grant of the President of Russian Federation for the State Support of Russian Scientists PhD, contract 14.Z56.16.5425-МК.

Bibliography:

1. Ковалевский К.А. Технология бродильных производств // Киев: ИНКОС. 2004. 340 с.

2. Turner, A. Biosensors: Sense and sensibility // Chem. Soc. Rev. ‒ 2013. ‒ V. 42 ‒ P. 3184–3196.

3. Backer M., Rakowski D., Poghossian A., Biselli M., Wagner P., Schцning M. J. Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis // Journal of Biotechnology. ‒ 2013. ‒ V. 163, I. 4. ‒ P. 371-376.