Biomarker detection using GST-based permittivity-asymmetric metasurface. (March 2023)

• Record Type: Journal Article
• Authors: Negm, Ayman; Howlader, Matiar M.R.; Bakr, Mohamed; Ali, Shirook
• Is Part Of: Materials & design. Volume 227(2023)
• Publication Date: 2023-03
• Subjects: Amide -- Asymmetric -- BIC -- Biomarker -- Detection -- GST -- Metasurface -- Permittivity -- MIR; BaF2 Barium Flouride -- BIC Bound states in the continuum -- FTIR Fourier Transform Infrared -- GST Germanium Antimony Telluride -- PCM Phase-change material -- MIR Mid-infrared; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2023.111747
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: Employed Ge3 Se2 Te6 phase-change material, for the first time, for tunable generation of sharp resonance by breaking the bound-state symmetry. Achieved robust reflectance amplitude (above 60%) against losses induced by phase change of Ge3 Se2 Te6 . Accomplished a resolution of 3 cm-1 within amide I band (1530–1553 cm-1) by tuning the crystalline percentage of Ge3 Se2 Te6 between 0 % and 60 %. Observed attenuation of the resonance amplitude by placing analyte over the metasurface without shifting the resonance wavelength. Abstract: Non-invasive detection of biomarkers can help in the early screening of lethal diseases, such as cancer and Alzheimer's. In this paper, we present a numerical study of a high-quality resonant permittivity-asymmetric metasurface that offers tunability in the mid-infrared range by employing the phase change property of Germanium Antimony Telluride, Ge3 Sb2 Te6 (GST326). In this approach, we used dissimilar materials of ellipse-shaped nanopillars, and shifted the nanopillars from their center positions to break the symmetry-protected bound state and generate a high-Q resonance sufficient for detecting trace amounts of analytes. The peak location of the resonance can be controlled by tuning the crystallization state of GST326 for broadband retrieval of analyte signatures. We performed a grid search to optimize the design parameters to obtain a tuning range that matches the absorption band of amide I and II groups. As a proof of concept, we demonstrate sensing of a thin protein layer using the proposed metasurface and we show how our structure is sensitive to the imaginary part of the analyte refractive index and how the permittivity-asymmetry resonance is robust against crystallization losses. We also propose a layout for a practical device that can be used for biomarker detection applications.