Some issues such as tunneling current, boron diffusion through the ultra-thin silicon dioxide gate dielectric and leakage current in the current metal oxide semiconductor field effect transistor cause that researchers have tried to find an alternative high—K gate dielectric material. For this purpose, Fe3O4/ZnO nanocomposite, as a possible gate dielectric, is synthesized by sol–gel method and its electrical and nanostructural properties are studied by X-ray diffraction, Leakage current–voltage and Fourier transform infrared spectroscopy, GPS 132A, cyclicvoltammetry and field effect scanning electron microscopy techniques. The obtained results show that, with increasing the aspect ratio and reducing the size of the nanocomposite, the electrical characterization improved. Fe3O4/ZnO with 1:10 molar ratio can be considered not only as a good gate dielectric of nano scale transistor, but also one of the options in the field of cyborg; a branch of medical science for integrate electronic structures of biological tissue to therapeutic targets and sensors.