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Updated: May 29, 2026
A Label-free Technique for the Spatio-temporal Imaging of Single Cell Secretions
Published on: November 23, 2015
A High-resolution metal-insulator-metal plasmonic biosensor with concentric ring resonators for carcinoembryonic
Hamid Bahador1, Hadi Izadiyar2, Azadeh Nilghaz3
1Department of Electrical and Computer Engineering, University of Mohaghegh Ardabili, Ardabil, Iran. hamid.bahador@uma.ac.ir.
Abstract:
High-resolution optical sensors are vital for detecting subtle refractive index variations associated with biomolecular interactions, such as changes in carcinoembryonic antigen (CEA) concentration. This work presents a compact metal-insulator-metal (MIM) plasmonic sensor with two concentric ring resonators, numerically investigated using finite-difference time-domain simulations. Structural parameters are optimized to maximize field confinement and resonant mode coupling, yielding a sensitivity of 1035 nm/RIU, a resonance linewidth of 3.75 nm, and a figure of merit of 276 RIU⁻¹. The sensor demonstrates precise spectral shifts corresponding to minute refractive index changes linked to CEA, while the influence of surface-bound layers and fabrication tolerances is also assessed to ensure robustness under practical conditions. These results highlight the sensor's potential as a high-resolution, label-free platform for monitoring CEA in biological samples.
