We have designed a terahertz highly sensitive plasmonic sensing device. According to the concept of the sensing phenomena, we have chosen the cylindrical metal structure which is independent to the polarization of the incident wave. To analyse its sensing functionality we employ the magnetic resonance. The amplitude modulation and a shift in the resonant frequency of the terahertz transmission have been done by depositing a thin film overlayer on the surface of the metallic apertures. Refractive index and the thickness of the overlayer is the main reason to investigate the frequency shift and the amplitude modulation for deciding the sensing capability of the proposed structure. From this analysis, we obtained that the proposed absorber provided the better sensing which is used for biological applications. © 2020 National Institute of Optoelectronics. All rights reserved.