Biopolymers and cell. 1996; 12 (1): 53 - 57

Conductometric urease microbiosensor based on thin-film interdigitated electrodes for urea determination

Sergey V. Dzyadevich*, Gleb A. Zhylyak, Alexey P. Soldatkin, Anna V. El'skaya

he characteristics of conductometric urease microbiosensor based on thin-film inter-digitated electrodes for urea determination have been studied. Urease has been immobi¬lized by cross-linking with bovine serumalbumin using glutaraldehyde. The resulting con¬ductivity 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.