Preparation of potentiometric enzyme electrode for urea based on enzyme immobilization by 60% quaternized poly(4-vinyl)pyridine

Based on electrostatic interaction between 60% quaternized poly (4-vinyl)pyridine and urease molecules, which can be immobilized on the surface of pH glassy electrode. By means of this technique, the enzyme electrode for urea was prepared. In experiments, we discussed in detail effects of kinds, concentration and pH of media on response of the electrode. In 0.025 mol/L phosphate buffer solution (pH 6.8), the linearity range is between 1 x 10(-4) and 6 x 10(-2) mol/L and the detection limit is 1 x 10(-4) mol/L. The electrode has been applied to the determination of urea in standard serum and recovery is between 92.9% and 107.0%.