Engineered Graphene-Integrated 3D curved hyperbolic metamaterial nanolenses for advanced multiselective nanophotonic biosensing

Abstract

Plasmonic sensing based on nanostructured multilayer hyperbolic metamaterials is an ultra-sensitive analytical tool for detecting biomolecules in a wide range of selectable wavelengths, which has high potential in clinical diagnostics and biomedical research. In this paper, we propose a novel plasmonic biosensor architecture based on a three-dimensional cylindrical hyperbolic metamaterial (CHMM) nanolens integrated with a rounded-corner gold grating. The nanolens consists of alternating graphene and Al₂O₃ bilayers, engineered in a curved cylindrical geometry, which significantly enhances light–matter interactions compared to conventional flat HMM platforms. The incorporated Au nanograting efficiently couples the incident TM-polarized plane wave into the high-k bulk plasmon polariton modes supported by the graphene–dielectric multilayers. This combined effect leads to strong field confinement, increased interaction volume with analytes in the surrounding water medium, and improved angular stability. Using the finite-difference time-domain (FDTD) method, the reflection spectra and resonant dip characteristics were analyzed under variations of structural parameters and graphene Fermi energy levels. Simulation results demonstrate that the proposed biosensor achieves a sensitivity of 5348 nm·RIU⁻¹ and a figure of merit of 26.36 RIU⁻¹, confirming its potential for selective and ultra-sensitive biomolecular detection.