Bismuth Tri-borate–Blue Phosphorus-Based Surface Plasmon Sensor for Chlorothalonil Pesticide Detection

Chlorothalonil is a widely used broad-spectrum fungicide and plays an important role in safeguarding human health due to its use in ensuring the safety and quality of food and water supplies. In this study, an effective surface plasmon resonance (SPR) biosensor for chlorothalonil pesticide detection based on the heterostructure between bismuth tri-borate (BiB₃O₆) and Blue Phosphorus (BlueP)/TDMCs was designed. The sensor design followed the Kretschmann configuration and the metallic layer to excite surface plasmons was silver (Ag). Furthermore, several BluePs (e.g., BlueP/WS₂, BlueP/MoSe₂, and BlueP/MoS₃) are investigated as constituent elements of the BlueP/TDMCs heterostructure. The transfer matrix method and angular interrogation methods are applied to investigate the proposed sensor at 633-nm wavelength. At the start of the study, optimization is performed for the thickness of both the prism and Ag layer to get maximum sensitivity along with minimum reflectance. Afterward, the impact of this structure is assessed by evaluating its sensitivity performance concerning several other configurations that have been layer-specified. Moreover, the optimal reported sensing properties regarding SPR sensor parameters for various chlorothalonil pesticide concentration analyses. Finally demonstrated excellent results with a sensitivity of 98.35°/RIU, a quality factor (QF) of 207.33 RIU⁻¹, and detection accuracy (DA) of 22.81 granted with the precise features of developed structures. This investigation introduced the performance of the combined sensitive factor (CSF) of 303.83, which shows the SPR’s overall performance. The results demonstrate a notable improvement compared to existing research.