Design and Analysis of a Terahertz Metasurface-Based Refractive Index Sensor for Hemoglobin Detection With Behaviour Prediction Using Polynomial Regression

This study presents the design and analysis of a novel terahertz metasurface-based refractive index sensor for hemoglobin detection. The proposed sensor incorporates advanced materials including graphene, MXenes, SrTiO₃ and gold on a SiO₂ substrate. Comprehensive parametric optimization was conducted using COMSOL Multiphysics to enhance the sensor's sensitivity and overall performance. The optimized design demonstrated high sensitivity to hemoglobin concentration changes, with distinct transmittance responses observed for concentrations ranging from 10 g/l to 40 g/l. Electric field intensity analysis verified the sensor's transmission characteristics across different frequencies. Performance metrics such maximum sensitivity of 1000GHzRIU^-1, minimum FOM of 2 RIU^-1, minimum detection limit of 0.044 among other performance parameters which demonstrates exemplary results. Furthermore, polynomial regression models were employed to predict the sensor's behaviour under various parametric conditions, achieving maximum R² scores between 0.86 and 1 across different test cases.