Biosensor made from metal oxide is reported to be useful for sensing urea levels in the human body, NiO nanoparticles have successfully been utilized to make urea biosensors. Ni-based electrodes are favorable for making a low-cost urea biosensor. Fe-doped NiO nanoparticles were prepared by the sol-gel method. Different concentrations of Iron doping were done in NiO and its sensing response was measured. XRD characterization was performed to determine the material's structure, phase purity, and crystallinity. Also, this characterization showed that the NiO compound is pure and single phase with a cubic structure. CV, time response FTIR, and UV–Visible spectroscopy were performed on the pure and Fe-doped NiO samples. The CV curve of a Fe-doped NiO-modified electrode in the presence of urea showed an excellent electrochemical response. Furthermore, it was also observed that with the increase in Fe doping, the sensing response and absorption properties of the samples were enhanced.