Figure 5From: Nano- and microsized zeolites as a perspective material for potentiometric biosensors creation Calibration curves of different urea biosensors. They were based on: first (1), second (2), and third (3) variant of coimmobilization of urease with zeolite H+-BEA-30. Measurements were conducted in 5 mM phosphate buffer, pH 7.2.Back to article page