Paper 14110-39
Paper 14110-39
High-FOM surface plasmon resonance sensors through dielectric and structural engineering
On demand | Presented live 14 April 2026 
Abstract
A three-layer plasmonic sensor based on aluminum, carbon nanotubes (CNTs), and fluorinated graphene is proposed for detecting fat concentration in milk in the near-infrared region. The design follows the Kretschmann configuration to achieve surface plasmon resonance (SPR) at the metal-dielectric interface. Aluminum provides a cost-effective plasmonic base, while CNTs and fluorinated graphene enhance field confinement and improve interaction with the sensing medium. This hybrid structure enhances plasmon coupling and increases sensitivity to small refractive index changes associated with variations in milk fat content. The optimized sensor achieves a high sensitivity of 172°/RIU and a figure of merit (FOM) of 747.82 RIU-1, demonstrating nearly 7× improvement over conventional SPR designs. The enhanced performance results from sharper resonance characteristics and improved plasmon confinement due to the nanostructured layers. The proposed sensor offers a simple, efficient platform for rapid, easy milk fat analysis and shows strong potential for food quality monitoring and other optical biosensing applications.
Presenter
Rahul Runthala
Birla Institute of Technology and Science, Pilani (India)
R. Runthala received his B.E. degree in electronics and communication engineering from JECRC, Jaipur, in 2009. He worked at CEERI-Pilani as a Project Assistant in Testing and Designing of B-Type Cathodes for TWT applications. He worked as a Lecturer and Assistant Professor at BK Birla Institute of Engineering and Technology (BKBIET), Pilani, from 2011 to 2023. He is working toward his Ph.D. in the Department of Electrical & Electronics Engineering, Birla Institute of Technology and Science, Pilani, India. His research work mainly focuses on SPR-based optical sensors.