Blood Hemoglobin Concentration Sensing by Optical Nano Biosensor-Based Plasmonic Metasurface: A Feasibility Study

Erratic in concentration of the blood hemoglobin (Hb) is pernicious and common disease in many humans worldwide. The establishment of Hb measurement led to finding bio-optics mechanisms for tunable and high sensitivity dual-band plasmonic metasurface (PM) configuration that studied for Hb concentration detection of blood and formed by a semiconductor integrated with metal and dielectric layers. However, finding particularly useful mechanisms without surgery is a safe method with several potentials in biomedical applications. In this paper, a biosensor based on surface plasmon resonances (SPRs) that is a label-free detection method is proposed to measure Hb concentration of blood. The presented sensing method is susceptible to being a dual-bands metasurface perfect absorber at room temperature to adjust the optical properties of the integrated semiconductor plasmonic structure. The modeling and numerical performance have been fulfilled based on the finite element method (FEM) using an electromagnetic field simulation software (CST). Also, to validate the numerical results, the transfer matrix method (TMM) was introduced as an analytical model. The analytical and numerical results show a good agreement. Results indicate maximum sensitivity, figure of merit (FoM), and quality factor ( Q ) as 315 nm/RIU, 398.8, and 1407.6, respectively. By controlling and harnessing the light-matter interaction in near-infrared (NIR) region, we obtained the giant electric field intensity enhancement (EFIE) as 5000 and the maximum absorption close to 1 in the first resonance peak of λ ₁ = 1.126 µm which is the best track of optical operation in NIR regime. By adding samples to the biosensor, different Hb concentrations of 0 g/L to 260 g/L have been detected from 1.11 µm to 1.17 µm. Furthermore, the proposed optical metasurface design can be utilized as a biosensor to measure the different content of Hb concentration in whole blood on a g/L scale, making it one of the best candidates for the future optical biosensors for biomedical applications.