Design of tunable gold metasurface refractive index biosensor using Ge2Sb2Te5 material

We present a tunable gold metasurface refractive index biosensor. The tunability is achieved by two different phases of Ge2Sb2Te5 (GST) material. The sensitivity of refractive index sensor is also enhanced by this GST material based metasurface biosensor design. The results in the form of absorption, electric field, and magnetic field are presented. The design is also observed for different geometrical parameter variations. The incident angle is also varied to observe its effect on absorption of the design. The crystalline phase of GST materials is giving better sensitivity compared to amorphous phase of GST. The proposed design results are compared with previously published design results. The comparison cl early shows that proposed design has better sensitivity compared to other designs. The proposed biosensor can become a building block for medical sensing devices. © 2022, National Institute of Optoelectronics. All rights reserved.