Characteristics and Stability of a Flexible Arrayed Uric Acid Biosensor Based on NiO Film Modified by Graphene and Magnetic Beads

In this study, the characteristics and stability of the nickel oxide (NiO) based uric acid biosensors modified with graphene and magnetic beads (MBs) were investigated. The sensitivity and linearity of the different membranes were compared by using the voltage-time (V-T) measurement system. Then, the electrochemical impedance spectroscopy (EIS) was used to prove that adding the modification could reduce the impedance of the thin films and improve the electron transfer feature. Furthermore, we successfully fabricated the MBs-uricase/rGO/NiO films as a sensing membrane for the NiO based biosensor, which was suitable for measuring the uric acid in this study. Thus, the NiO based uric acid biosensor showed the relatively higher average sensitivity and linearity of 38.279 mV/(mg/dL) and 0.966, respectively. Finally, in terms of stability, an investigated into both the interference effect and lifetime of the uric acid biosensor was conducted, and the satisfying stability in this regard was also shown.