SURFACE-ACOUSTIC-WAVE ENZYME SENSOR APPLIED TO THE KINETIC ASSAY OF ACID-PHOSPHATASE

The acid phosphatase hydrolysis of phenylphosphoric acid (at pH 5 and at 25 degrees C) with a new type of liquid-immersion surface acoustic wave enzyme sensor (SAW) is described, A mathematical model was derive d to estimate the kinetic parameters and to determine the concentratio ns of enzyme and substrate, The inhibition of the product to the enzym e activity was involved In the model. The Michaelis constant was estim ated to be 1.17 x 10(-4) mol l(-1). The recovery of the sensor system was 97.4-104.4% (n = 6). The effects of temperature and pH on the enzy me activity were discussed. The proposed model compared favourably wit h the linear method which indicated that the model gave more precise r esults.