Terahertz plasmonic biosensors with graphene-MXene-phosphorene heterostructures for ultra-sensitive dopamine detection: a machine learning enhanced approach

This study introduces a plasmonic biosensing platform tailored for dopamine detection in the terahertz (THz) frequency domain. The numerical simulations conducted in COMSOL Multiphysics reveal outstanding sensing performance, achieving a maximum sensitivity of 500 GHz/RIU within the 0.81–0.824 THz range. The proposed sensor demonstrates pronounced tunability through modulation of the graphene chemical potential and retains robust performance across varying incident angles. Electromagnetic field distribution analyses indicate optimal sensing conditions at 0.81 THz, where strong field confinement enhances analyte–resonator interaction. The incorporation of a multi-material metasurface architecture further augments both sensitivity and selectivity, ensuring reliable dopamine recognition. Additionally, polynomial regression models attain prediction accuracies approaching 100%, validating the consistency and reproducibility of the proposed design. Collectively, this work addresses pressing challenges in neurological biomarker detection by offering a highly sensitive, selective, and potentially scalable platform for clinical dopamine monitoring, with significant implications for early diagnosis and treatment management of neurological disorders.