High-performance bimetallic surface plasmon resonance biochemical sensor using a black phosphorus–MXene hybrid structure

A highly sensitive surface plasmon resonance biochemical sensor based on black phosphorus–MXene (Ti3C2Tx) hybrid structure and copper–nickel (Cu–Ni) bimetal layers is investigated analytically under angular interrogation technique. The use of Ni over Cu shows much sensitivity enhancement for the proposed sensor than on using single metal. Black phosphorus serves as an effective medium for enhanced light–matter interaction due to its layer-dependent direct and tunable bandgap. High metallic conductivity, hydrophilicity, larger surface area, and the large number of adsorption sites on the functionalized surface of Ti3C2Tx provide better sensing of analytes. We have achieved the highest sensitivity (304.47°/RIU) for the Cu–Ni bimetal configuration among all other MXene-based SPR biosensors proposed to date. It can be fabricated as a sensor chip for efficient sensing of analytes or biochemical molecules considering careful control of surface termination of Ti3C2Tx. The transverse magnetic electric field |Ez| is also plotted for the biochemical sensor to compute the sensing medium’s penetration depth.