Sensitivity Improvement of a MXene- Immobilized SPR Sensor With Ga-Doped-ZnO for Biomolecules Detection

Abstract

This work presents a surface plasmon resonance (SPR) sensor based on Gallium (Ga)-doped-Zinc oxide (ZnO) and Ti <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> (MXene) for sensitivity enhancement. The smaller resistivity and high conductivity of the pulsed layer deposited Ga-doped-ZnO are used to improve the sensitivity up to (264.59 °/RIU). The detection accuracy (0.1152°) and figure of merit (30.48 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> ) are also evaluated for the proposed sensor. The effects of using different prisms (SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , BaF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , CsF, and BK7), plasmonic metals (Au, Ag, Cu, and Al) and doping in ZnO (intermediate layer) on the performance parameters of the proposed SPR sensor are investigated for comparative analysis. The comparative performance analysis presents the maximum sensitivity for the SPR sensor structure: Prism SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Au/Ga-doped-ZnO/MXene. The field distribution at different layer interfaces of the SPR sensor configurations has also been analyzed using FEM simulations. This work is suitable for the detection of biomolecules and biochemicals