The Detection of Mercury, Cadium, and Arsenic by the Deactivation of Urease on Rhodinized Carbon

Heavy metal contaminations create high risk of health hazards across the world. Toxic metals deactivate valuable enzymes of the human body, causing a health hazard. In this paper we have reported a monitoring system for detection of a few heavy metal ions (e. g., mercury, cadmium, and arsenic). The process utilizes deactivation of the enzyme urease by the metal present in the sample. Many researchers studied the estimation of heavy metal ions by deactivation of enzyme urease that was immobilized on the surface of the electrode. The uniqueness of this present procedure is that no immobilization of enzyme was needed though the estimation was based on enzymatic analysis. The three-electrode screen-printed assembly with working electrode made of rhodinized (10%) carbon was used to oxidize ammonia produced by deactivated enzyme and urea. The system was thus suitable for amperometric measurement. It was also durable and could be used without any sample preparation. Calibration curves were constructed for pure samples of various concentrations (0-20 ppb) of the three heavy metal ions.