A Flexible Printed Circuit Board-Based ZnO Enzymatic Uric Acid Potentiometric Biosensor Measurement and Characterization

This study prepared an enzymatic potentiometric uric acid sensor based on zinc oxide (ZnO) and uricase. Also, we develop a potentiometric differential measurement system. We applied Nafion, APTES, and glutaraldehyde to immobilize the enzyme and increase sensitivity to prevent enzyme leakage. Thus, the uric acid sensor was integrated into FPCB which could provide flexibility to the sensor. In the uric acid concentration range of 2 mg/dL-10 mg/dL, we analyzed the characteristics of sensors with the voltage-time measurement system, measuring the average sensitivity, linearity, response time, limit of detection (LOD), and interference effects. The modification of Nafion and uricase improved the performance of the uric acid sensor.