Highly sensitive graphene terahertz biosensor for hemoglobin detection enhanced by stacking ensemble learning

This study introduces a graphene-based biosensor developed for hemoglobin detection in clinical and point-of-care use. Optimization through COMSOL Multiphysics produced high performance parameters. The sensor achieved a sensitivity of 200 GHz/RIU, operated between 1.319 and 1.331 THz, and exhibited quality factors from 0.915 to 2.439. Electric field distribution analysis showed maximum absorption at 1.325 THz with strong field localization along the resonator edges. A machine learning model using a Stacking Ensemble Regressor was applied to predict sensor performance, reaching an R 2 value of 1.0 for transmission spectra across different graphene chemical potentials and incident angles. The linear correlation between resonance frequency and refractive index (R 2 = 0.95447) confirms the sensor's accuracy for quantitative hemoglobin measurement. The biosensor enables rapid and precise hemoglobin detection, making it suitable for portable diagnostic use in resource-limited or urgent care settings.