MXene-Mediated Long-Range Surface Plasmon Resonance (LRSPR) Sensor at Near-Infrared Wavelength

In this study, a long-range surface plasmon resonance (LRSPR) sensor based on a dielectric buffer layer of Cytop, silver metal, and a two-dimensional (2D) nanomaterial layer of MXene is proposed and investigated for higher sensitivity, figure of merit (FoM), and penetration depth (PD). The proposed sensor is suitable for biomolecule detection at 1550 nm wavelength. Mxene is employed as an affinity/biorecognition element (BRE) layer to bind biomolecules owing to its unique sensing capabilities, which include strong steric affinity, high charge carrier density, hydrophilicity, and high stability, among other 2D materials. The maximal FoM of the proposed sensor achieved is 571.99/RIU at 400 nm of Cytop and 58 nm of Ag layer with MXene. The maximal penetration depth (PD) of the sensor achieved is 1447.95 nm at 1000 nm of Cytop and 50 nm of Ag layer. The excellent PD and FoM of the proposed LRPSR sensor indicate its significant potential for accurate sensing the large size biomolecules such as cancer cells, oligonucleotides, Escherichia coli bacteria, and B. anthracis bacteria.