Inverted bracket-shaped refractive index sensor with high Q-factor for biomedical applications

The domain of biosensing and bioimaging has received an impetus with the development of metamaterial absorbers. They can be used to detect the change in the refractive index in and around a cell which is further required in applications like cancer detection. In this paper, we propose a metamaterial absorber working in the terahertz frequency range for such biomedical applications. The sensor is formed by designing a set of concentric inverted brackets on gallium arsenide substrate. It yields an absorption rate >95% with a high quality factor of 593.04. The performance is governed by a fine sensitivity of 1.557 THz/RIU and consequent Figure of merit 311.4 RIU-1.