Application of urease conductometric biosensor for heavy-metal ion determination

• Published in: Sensors and actuators. B, Chemical Chemical, 1995, Vol.24 (1), p.145-148
• Main Authors: Zhylyak, G.A., Dzyadevich, S.V., Korpan, Y.I., Soldatkin, A.P., El'skaya, A.V.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biosensors; Biotechnology; Conductometry; Fundamental and applied biological sciences. Psychology; Heavy-metal ion determination; Methods. Procedures. Technologies; Thin-film interdigitated electrodes; Urease immobilizations; Various methods and equipments
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/0925-4005(95)85031-7

Urease conductometric biosensors consisting of interdigitated gold electrodes and enzyme membranes formed on their sensitive parts have been used for a quantitative estimation of general water pollution with heavy-metal ions. The measurements of the urease residual activity have been carried out in Tris-HNO 3 buffer after preincubation in model metal-salt solution. The detection limits, depending on preincubation time and dynamic ranges, have been determined in model solutions of heavy-metal ions. The sequence of metals ions relative to their toxicity toward urease is: Hg 2+ > Cu 2+ > Cd 2+ > Co 2+ > Pb 2+ > Sr 2+ > . The conditions for practical applications of the biosensors have been investigated and critically evaluated for optimization. Urease reactivation by EDTA after inhibition by heavy-metal ions has been demonstrated. The performance characteristics of the conductometric biosensor are discussed.