Graphene-Based Highly Sensitive Refractive Index Biosensors Using C-Shaped Metasurface

In this work, graphene-based metasurface infrared biosensors are presented. The C-shaped tungsten metasurface is placed over graphene material to achieve higher sensitivity. The sensitivity of biosensors depends on how the absorption peak is shifted by the addition of biomolecules over the sensor. The wavelength shift of 900nm is achieved for the proposed biosensors with haemoglobin biomolecules. The sensitivity of 2571 nm/RIU is achieved by using this graphene-based metasurface design. The sensitivity of hemoglobin biomolecules with urine biomolecules is also investigated and it is 3846nm/RIU. The sensitivity of the proposed biosensors is varied by changing the design parameters such as C-shaped tungsten metasurface thickness, C-shaped tungsten metasurface width, SiO
₂
layer thickness, and tungsten bottom layer thickness. The proposed biosensors design is also compared with other published researches and showing better sensitivity than these published researches. The optimized physical parameters are achieved in this paper. The proposed highly sensitive biosensors is having great potential to become a building block for medical biosensing devices and photovoltaic devices.