Performance Evaluation of Bimetallic Surface Plasmon Resonance Sensor Based on Ti3C2Tx (MXene)

Abstract

In this paper, sensitivity improvement of silver (Ag)–nickel (Ni)-based bimetallic surface plasmon resonance biosensor using a 2D material Ti3C2Tx is presented. Here, Ti3C2Tx serves as a bio-recognition (BRE) layer because of its excellent metallic conductivity, hydrophilic functionalized surface terminations, larger contact area and higher binding energies for attachment of biochemical molecules present in an aqueous solution. Through theoretical investigations, we evaluated numerous performance factors at optimized silver and nickel thicknesses. The bimetallic SPR biosensor shows the maximum sensitivity and maximum resolution than that of the proposed SPR sensor without using nickel. The thickness of the Ag and Ni layers with monolayer Ti3C2Tx are optimized to achieve the maximum sensitivity. At minimum reflectance condition, the sensitivity obtained is 248°/RIU at 28 nm of Ag and 15 nm of Ni layers with monolayer Ti3C2Tx. Results shows that the sensitivity can reaches up to 292°/RIU for refractive index variation of sensing medium from 1.330 to 1.335 at 633 nm wavelength, which is achieved at optimized bimetallic layers, 45 nm of Ag and 15 nm of Ni thicknesses.