Enhanced Ultra-High Sensitivity Surface Plasmon Resonance Refractive Index Sensor Based on Black Phosphorus and Corrugated Silver Layer Structure

In this study, we propose an enhanced ultra-high sensitivity prismatic surface plasmon resonance refractive index sensor. The core innovation of the sensor design lies in the integration of the two-dimensional nanomaterial black phosphorus with a corrugated silver layer. This synergistic combination significantly amplifies the interaction between the analyte and the sensing surface, thereby markedly enhancing the sensor’s performance. The influence of the corrugated silver layer and multi-layer black phosphorus on the sensing performance of the proposed sensor was analyzed using numerical simulations. By optimizing structural parameters, including the number of black phosphorus layers and the thickness and period of the corrugated silver layer, the sensor achieved ultra-high sensitivity and an exceptional figure of merit. Within the refractive index range of 1.330 RIU to 1.335 RIU, the sensor exhibited an average sensitivity of 1630°/RIU and a figure of merit of 217.333/RIU. Compared with previously reported prismatic surface plasmon resonance refractive index sensors, the proposed sensor exhibits significantly enhanced angle sensitivity. This sensor is particularly well-suited for detecting biomolecules, including the SARS-CoV-2 virus. It demonstrates substantial potential for applications in high-precision biomedical detection and medical diagnostics.