Surface plasmonic resonance (SPR) is integrated into a whispering-gallery mode (WGM) optical microsensor to augment sensitivity in this study. The performance of such WGM silica ring sensors of 20 µm in size with an Ag or Au metal core was evaluated for detection of small respiratory viruses such as COVID-19 via the finite-element modeling. Compared with pure WGM sensors, the integration with SPR enhances sensitivity by 3–5 times and facilitates combination with the polymerase chain reaction method to achieve fast, accurate, and specific virus detection. The presence of a single respiratory virus of 70 to 100 nm in diameter in air environment could shift the sensor resonance wavelength by 36 to 64 pm in the case of an Au metal core or by 34 to 63 pm of an Ag metal core. With use of a general-purpose optical analyzer of 10 pm resolution, a single airborne virus of 20 nm in size is detectable using the proposed hybrid sensor. This corresponds to about 0.005 vol. %. For viruses in aqueous solution, the detection limit rises to about 0.2 vol. %. A fundamental enhancement factor based on relative electric energy ratio is introduced and defined to analyze and quantify sensitivity enhancement for the first time, to the best of our knowledge.

中文翻译：

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具有回音壁模式和表面等离子体共振的集成传感器，用于增强病毒检测

在这项研究中，表面等离子体共振 (SPR) 被集成到回音壁模式 (WGM) 光学微传感器中以提高灵敏度。通过有限元建模评估了这种尺寸为 20 µm 的 WGM 二氧化硅环传感器的性能，用于检测小型呼吸道病毒，如 COVID-19。与纯 WGM 传感器相比，与 SPR 的集成提高了 3-5 倍的灵敏度，并有利于与聚合酶链反应方法相结合，实现快速、准确、特异的病毒检测。空气环境中直径为 70 到 100 nm 的单个呼吸道病毒的存在可能会使传感器共振波长在 Au 金属核的情况下移动 36 到 64 pm，或者在 Ag 金属核的情况下移动 34 到 63 pm。使用分辨率为 10 pm 的通用光学分析仪，使用提议的混合传感器可以检测到大小为 20 nm 的单个空气传播病毒。这对应于大约 0.005 vol。%。对于水溶液中的病毒，检测限上升到约 0.2 vol。%。据我们所知，首次引入并定义了基于相对电能比的基本增强因子来分析和量化灵敏度增强。