Investigation of Flexible Arrayed Urea Biosensor Based on Graphene Oxide/Nickel Oxide Films Modified by Au Nanoparticles

In this work, the flexible arrayed urea biosensor is composed of silver paste electrodes by screen printing technology. The sensing film is made of the nickel oxide (NiO) by radio frequency (R.F.) sputtering system and then modified by Au nanoparticles (Au NPs) and graphene oxide (GO). The average sensitivity, response time, interference effect, and electrochemical impedance of urea biosensors are analyzed by the voltage- time (V-T) measurement system and electrochemical impedance spectroscopy (EIS). The surface morphology of the biosensor is analyzed by scanning electron microscope (SEM). The results show that the flexible arrayed urea biosensor has excellent average sensitivity over a wide concentration range (0.01-100 mM) of 57.16 mV/decade, linearity of 0.998, a response time of 25 s, a limit of detection (LOD) of 7.64 μM, and an excellent selectivity.