A Tantalum Disulfide (TaS2) Mediated Long-Range Surface Plasmon Resonance Refractive Index Sensor with Improved Performance

In this manuscript, we comprehensively evaluate a newly devised biosensor that utilizes the Kretschman configuration and incorporates Tantalum Disulfide (TaS2) for Long Range Surface Plasmon Resonance (LRSPR). We optimized the performance of the sensor by simulating with different metals [specifically, gold (Au), silver (Ag), and aluminium (Al)] and four distinct dielectric buffer layers (namely, LiF, Teflon, Cytop, and MgF2) using MATLAB software. The most favourable configuration emerges when we employ a 28 nm thick Al layer and 800 nm thick MgF2 layer. It yields exceptional performance parameters, particularly in response to variations in the refractive index (RI) of the sensing medium (SM, nSM = 1.33–1.38). These parameters include a reduced full width at half maximum (FWHM) of 0.1 Deg., enhanced detection accuracy (DA) at 10 (1/Deg.), imaging figure of merit (IFOM) measuring 26,903 [(Deg. RIU)]−1, an angular figure of merit (FOMang.) of 189.9 (RIU−1), and an imaging sensitivity (Simg.) of 2690.3 RIU−1 at a wavelength of 633 nm. Comparing the LRSPR sensor to the conventional SPR (CSPR) sensor, it significantly outperforms them with 7.053 times higher Simg., 57.84 times higher IFOM, 8.20 times higher DA, and 4.61 times higher FOMang. The analysis performed using COMSOL Multiphysics software demonstrates that the proposed LRSPR biosensor achieves a notably deeper penetration depth (PD) of 348.25 nm, surpassing the PD of CSPR sensors (PD = 197.65 nm). This remarkable PD underlines the potential of the proposed sensor for highly precise and sensitive RI sensing, placing it as a promising contender for diverse biomedical applications.