The screen-printed electrodes modified with whole bacteria cells as a basis of amperometric biosensor

Kamanin S. S., Arlyapov V. A.

Tula State University

In recent years, biosensor analysis methods are developing intensively. Biosensors allow continuous monitoring of biochemical processes, environmental monitoring, determination of the food quality, its composition, content of toxins and antibiotics. Immobilized whole living cells have found use in variety of biosensors. In this paper, bacteria cells Gluconobacter oxydans were immobilized on the surface of the transducer – graphite screen-printed electrode. Screen-printed electrodes – are devices obtained by applying paste composition on various plastic or ceramic supports. The advantages of applying screen-printed electrodes in biosensing include ability of electrodes miniaturization, their versatility and low cost.

The aim of this work was to develop modified screen-printed electrodes based on bacteria G. oxydans, immobilized in the cross-linked gel of bovine serum albumin (BSA) for ethanol and glucose determination. Screen-printed graphite electrodes and potentiostat EmStat (PalmSens, Netherlands), integrated with a personal computer were used for signal registration. Neutral red was used as an electron transport mediator. Signal processing performed via specialized software – PalmSens PStrace.

As a result of the work, screen-printed electrodes modified with microorganisms Gluconobacter oxydans for analysis of low concentrations of ethanol and glucose were developed. Main characteristics of the fabricated electrodes were obtained. Detection ranges of ethanol and glucose accounted 0.12-2.0 mM and 0.6-4.5 mM, respectively. It is shown that the signal of modified electrodes remained stable for 5 days of intensive use. The relative standard deviation at carrying out 10 concurrent measurements of the same glucose concentration with single modified electrode equals to 6%. The relative standard deviation of the results of determination of the same glucose concentration with set of 10 modified electrodes was 12%. The analysis of real samples using the developed electrodes was carried out. The obtained values coincide with the values obtained by the reference methods (high performance liquid chromatography, gas chromatography) considering confidence intervals.

The work was supported by Grant of the President of Russian Federation for the State Support of Russian Scientists ‑ PhD, contract 14.Z56.14.330-MK and RFBR grant 13-05-97513.