Tunable Multilayer Surface Plasmon Resonance Biosensor for Trace-Level Toxin Detection
Suripto Bhuiyan, Michael Geller
TL;DR
The study tackles trace toxin detection by designing a tunable multilayer surface plasmon resonance sensor in the Kretschmann configuration that incorporates black phosphorus and 2D transition metal dichalcogenides. It combines metal layers (Ag/Au), BP, and TMDs to enhance evanescent-field interaction, narrow the resonance and increase the figure of merit, quantified by $S = \frac{\Delta \theta_{SPR}}{\Delta n_s}$, $FWHM$, and $FoM = \frac{S}{FWHM}$. Finite-element simulations reveal that the Ag-BP configuration achieves approximately $3200\,^{\circ}/\mathrm{RIU}$ sensitivity, a $FWHM$ of about $1.5^{\circ}$, and a FoM around $2133$, outperforming Ag-Au and Ag-MoS$_2$ designs. These results indicate a more capable platform for real-time, label-free toxin sensing with potential applications in environmental monitoring and biochemical analysis, pending future experimental validation.
Abstract
This paper presents a comprehensive study on a novel multilayer surface plasmon resonance (SPR) biosensor designed for detecting trace-level toxins in liquid samples with exceptional precision and efficiency. Leveraging the Kretschmann configuration, the proposed design integrates advanced two-dimensional materials, including black phosphorus (BP) and transition metal dichalcogenides (TMDs), to significantly enhance the performance metrics of the sensor. Key innovations include the optimization of sensitivity through precise material layering, minimization of full-width at half-maximum (FWHM) to improve signal resolution, and maximization of the figure of merit (FoM) for superior detection accuracy. Numerical simulations are employed to validate the structural and functional enhancements of the biosensor. The results demonstrate improved interaction between the evanescent field and the analyte, enabling detection at trace concentrations with higher specificity. This biosensor is poised to contribute to advancements in biochemical sensing, environmental monitoring, and other critical applications requiring high-sensitivity toxin detection.