Sensitive Hemoglobin Concentration Sensor Based on Graphene-Plasmonic Nano-structures

In this paper, half-cylindrical-shaped rods are arranged in a row in order to form hemoglobin concentration sensors. The proposed structures can effectively detect hemoglobin concentrations in blood samples. Five individual structures based on graphene-plasmonic combinations are proposed and investigated. The proposed structures are made of different layers of Au, Ag, SiO₂, and graphene. Different plates and cylindrical-shaped graphene layers are introduced in the structures to improve the functionality (absorption peak value and wavelength) of the absorber (sensor). Adding more Au layers strengthens the confinement of the incident electromagnetic waves and improves the absorption factor. Also, in the proposed structures, for improving the results, the effects of the chemical potential of graphene layers and "G" (graphene layer thicknesses) on the absorption peak and wavelength are considered. The final suggested structure indicates unity absorption peak and thus can be utilized in wide ranges of applications. As a refractive index bio-sensor, the structure is considered for detecting hemoglobin concentrations in blood samples which indicates a reasonable sensitivity factor of 570 nm/RIU.