Study on the urease activity in different plant seeds and clinical analysis of urea in human body fluids by a surface acoustic wave enzyme sensor system

Urease was extracted from several kinds of plant seeds and the kinetic frequency response, the urease activity, Michaelis constants and other kinetic parameters were measured by means of a new device, i.e. a surface acoustic wave (SAW) enzyme sensor system, which was composed of a 61 MHz SAW resonator and a pair of parallel platinum electrodes. Influences such as extracting conditions, pH and temperature and the specificity were also investigated. The method has been successfully applied in the clinical assay of urea in human urine and blood. The results are in agreement with the reported values and also support the clinical diagnosis.