Biopolym. Cell. 1996; 12(1):53-57.
Conductometric urease microbiosensor based on thin-film interdigitated electrodes for urea determination
1Dzyadevich S. V., 1Zhylyak G. A., 1Soldatkin A. P., 1El'skaya A. V.
  1. Institute of Molecular Biology and Genetics, NAS of Ukraine
    150, Akademika Zabolotnoho Str., Kyiv, Ukraine, 03680


The characteristics of conductometric urease microbiosensor based on thin-film inter-digitated electrodes for urea determination have been studied. Urease has been immobilized by cross-linking with bovine serumalbumin using glutaraldehyde. The resulting conductivity changes are produced by enzymatically catalyzed hydrolysis of urea. This process for both immobilized enzyme and soluble one is described by the classic laws of enzymatic kinetics. The influence of ionic strength, pH and buffer capacity of the samples on the biosensor response has been thoroughly tested. The results have been discussed concerning urea concentration analysis in human blood.


[1] Lehninger AL. Grundkurs in biochemie. Berlin: Gruyter Verlag, 1985.
[2] Cullen DC, Sethi RS, Lowe CR. Multi-analyte miniature conductance biosensor. Analytica Chimica Acta. 1990;231:33–40.
[3] Shu’ga AA, Dzydevich SV, Soldatkin AP, Patskovsky SV, Strikha VI. Conductometric biosensors for glucose and urea determination based on microfabricated thin-film interdigigated array-electrodes. Biology Italiani. 1993;23(6):40-45.
[4] Lawrence AJ, Moores GR. Conductimetry in enzyme studies. Eur J Biochem. 1972;24(3):538-46.
[5] Shul'ga AA, Soldatkin AP, El'skaya AV, Dzyadevich SV, Patskovsky SV, Strikha VI. Thin-film conductometric biosensors for glucose and urea determination. Biosens Bioelectron. 1994;9(3):217-23.
[6] Soldatkin AP, El'skaya AV, Shul'ga AA, Jdanova AS, Dzyadevich SV, Jaffrezic-Renault N, Martelet C, Clechet P. Glucose sensitive conductometric biosensor with additional Nafion membrane: reduction of influence of buffer capacity on the sensor response and extension of its dynamic range. Anal Chim Acta. 1984;288(3):197–203.
[7] Reithel FG. The enzymes. Ed. P. D. Boyer. New York: Acad. Press, 1977. 3rd edn.
[8] Bubriak OA, Khustochka LN, Soldatkin AP, Starodub NF. Study of immobilization and properties of urease for creation of a biosensor based on semiconductor structures. Ukr Biokhim Zh. 1992;64(1):66-71.
[9] Khmelevskiy YUV, Usatenko OK. Basic human biochemical constants in norm and pathologies. Kiyev: Zdorov'ye, 1987.