Biopolymers and cell. 1997; 13 (5): 377 - 379

Urease-based biosensor with improved sensitivity for heavy meta! ions analysis

A. P. Soldatkin

Potcntiometric biosensors which consist of two ISFET structures covered with immobilized enzyme (urease) can be used for quanti¬tative estimation, of water pollution with heavy metal ions. The measurements of the residual enzyme activity have been carried out in Tris-HCl buffer (pll 7,4) after preincubation in model CuCl2 solution. It was shown that sensor sensitivity to inhibitor con¬centration depends strongly on enzyme immobilization method. The lowest detection limit has been obtained for urease biosensor modified by negatively charged additional Nafion membrane.