A strong light coupling between core-guided mode and metal layer leads to the enhancement of plasmonic sensor performance significantly. In this work, a plasmonic metal coated micro-channel based surface plasmon resonance sensor is proposed where a micro-channel is introduced to increase the mode coupling by reducing the distance between the core and analyte channel. Gold (Au) is considered to coat the micro-channel and generate surface plasmon on the fiber surface. Titanium dioxide (TiO₂) is employed to stick the Au layer tightly with the silica which assists in shifting the sensing wavelength from visible to mid-IR region. The light-guiding and bio-sensing properties of the proposed D-shaped sensor performance is numerically investigated by employing the finite element method. The sensor obtained maximal wavelength and amplitude sensitivities of 1,21,000 nm/Refractive index unit (RIU) and 1,405 RIU⁻¹, respectively in the x-polarized mode. Moreover, the sensor exhibits an extremely high resolution of 8.26 × 10⁻⁷ RIU and the limit of detection (LOD) is 6.83 × 10⁻¹² RIU²/nm, respectively, in the wavelength interrogation technique. To the best of our knowledge, the proposed sensor shows the highest wavelength sensitivity, resolution and LOD when compared to the existing PCF based SPR sensors. Due to the extremely sensitive response, the proposed sensor will enhance the unknown analyte detection capability significantly. Furthermore, the broad sensing range of analyte refractive index (RI) variation from 1.33 to 1.44 makes the sensor suitable for biochemical as well as medical diagnostic applications.

核心引导模式和金属层之间的强光耦合导致等离子体传感器性能的显着提高。在这项工作中，提出了一种基于等离子金属涂覆的微通道的表面等离振子共振传感器，其中引入了微通道，以通过减少核心与分析物通道之间的距离来增强模式耦合。金（Au）被认为可以覆盖微通道并在纤维表面产生表面等离激元。二氧化钛（TiO ₂）用于将Au层与二氧化硅紧密粘合在一起，这有助于将传感波长从可见光区域转换到中红外区域。通过采用有限元方法，对所提出的D形传感器性能的光导和生物传感特性进行了数值研究。传感器在x偏振模式下分别获得了1,21,000 nm /折射率单位（RIU）和1,405 RIU ^-1的最大波长和幅度灵敏度。此外，该传感器具有8.26×10 ^-7 RIU的极高分辨率，并且检测极限（LOD）为6.83×10 ^-12 RIU ²在波长询问技术中分别为λ/ nm。据我们所知，与现有的基于PCF的SPR传感器相比，拟议的传感器显示出最高的波长灵敏度，分辨率和LOD。由于反应极其灵敏，因此建议的传感器将显着增强未知分析物的检测能力。此外，分析物折射率（RI）的变化范围从1.33到1.44宽泛，使该传感器适用于生化和医学诊断应用。