Sensitivity enhancement of a graphene, zinc sulfide-based surface plasmon resonance biosensor with an Ag metal configuration in the visible region

A biosensor based on the modified Kretschmann configuration is proposed here. The sensitivity of the conventional prism-based sensor using angular interrogation is low. To enhance the sensor's performance, layers of zinc sulfide (ZnS) and graphene have been deposited over the metal layer. The angular interrogation technique is used to analyze the performance of the sensor. The thickness of the Ag metal has been optimized. The thickness of the Ag metal is taken as 50 nm because minimum reflectance has been achieved. With the combinations of the four layers of ZnS and one graphene layer, the maximum sensitivity attained is 292.8∘/RIU\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$292.8^\circ /RIU$$\end{document}. Performance parameters such as detection accuracy, FWHM, and quality factor of the sensor have been evaluated as obtained as 0.16 deg-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{ deg}}^{ - 1}$$\end{document}, 6.37 deg\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{ deg}}$$\end{document}, 46 RIU-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$RIU^{ - 1}$$\end{document}, respectively. The proposed sensor has potential application in the field of biochemical and biological analyte detection.