A novel immunosensor for detecting Newcastle disease virus (NDV) was developed using excessively tilted fiber grating (Ex-TFG) coated with gold nanospheres (AuNs). AuNs were coated on the Ex-TFG surface via Au–S bonds using 3-mercaptopropyltrimethoxysilane (MPTMS), and the activated staphylococcal protein A (SPA) was linked to AuNs by covalent bonds via cysteamine. AuNs greatly enhanced the impact of the analyte on the fiber cladding mode through the local surface Plasmon resonance (LSPR) effect, thus improving the detection limit and sensitivity of the immunosensor. Meanwhile, SPA enhanced the bioactivity of anti-NDV monoclonal antibodies (MAbs), thus promoting the effectiveness of specific binding events on the fiber surface. Immunoassays were performed by monitoring the resonance wavelength shift of the proposed sensor under NDV samples containing different particle amounts. Specificity was assessed, and clinical tests for NDV were performed by contrast experiments. Experimental results showed that the detection limit for NDV was about 5~10 times improved compared to that of reference Ex-TFG without AuN treatment. Moreover, the novel biosensor was reusable and could potentially be applied in clinic.

使用覆盖金纳米球（AuNs）的过度倾斜的光纤光栅（Ex-TFG），开发了一种用于检测新城疫病毒（NDV）的新型免疫传感器。使用3-巯基丙基三甲氧基硅烷（MPTMS）通过Au-S键将AuNs涂覆在Ex-TFG表面，活化的葡萄球菌蛋白A（SPA）通过半胱胺通过共价键与AuNs连接。AuNs通过局部表面等离子体共振（LSPR）效应大大增强了分析物对光纤包层模式的影响，从而提高了免疫传感器的检测极限和灵敏度。同时，SPA增强了抗NDV单克隆抗体（MAb）的生物活性，从而提高了纤维表面特异性结合事件的有效性。通过监测所建议的传感器在含有不同颗粒量的NDV样品下的共振波长偏移来进行免疫分析。评估特异性，并通过对比实验进行NDV的临床测试。实验结果表明，与未经AuN处理的参比Ex-TFG相比，NDV的检出限提高了约5〜10倍。而且，新型生物传感器是可重复使用的，并有可能在临床中应用。