In this study, the covalently fixed “end-on” orientation of a monoclonal Listeria monocytogenes antibody (mAb-Lis) to amino terminated oligo (ethylene glycol)-capped gold nanoparticles (NH₂-TEG-AuNPs) was used to fabricate an in-house lateral flow strip (LFS), namely, the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS. The aim was to evaluate the performance of the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS in detecting L. monocytogenes. The proposed LFS enabled the sensitive detection of L. monocytogenes in 15 min with a visual limit of detection of 10² CFU/mL. Quantitative analysis indicated an LOD at 10 CFU/mL. The fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS showed no cross-reactivity with other pathogenic bacteria and practical performance across different food matrices, including human blood, milk, and mushroom samples. Furthermore, the clinical performance of the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS for detecting L. monocytogenes was evaluated by using 12 clinical samples validated by the hemoculture method. It demonstrated excellent concordance with the reference methods, with no false-positive or false-negative results observed. Therefore, the fixed “end-on” Lis-mAb-NH-TEG-AuNPs LFS serves as a promising candidate for a point-of-care test (POCT), enabling the rapid, precise, and highly sensitive detection of L. monocytogenes in clinical samples and contaminated food.

中文翻译：

---

基于抗体共价固定“端上”方向的侧流试纸条的评估，用于单核细胞增生李斯特氏菌检测


在本研究中，单核细胞增生李斯特氏菌单克隆抗体 (mAb-Lis) 与氨基末端寡聚（乙二醇）封端的金纳米颗粒 (NH ₂ -TEG-AuNPs) 共价固定“端上”方向用于制造内部侧流试纸条（LFS），即固定“端上”Lis-mAb-NH-TEG-AuNPs LFS。目的是评估固定“末端”Lis-mAb-NH-TEG-AuNPs LFS 在检测单核细胞增生李斯特菌中的性能。所提出的 LFS 能够在 15 分钟内灵敏地检测单核细胞增生李斯特菌，视觉检测限为 10 ² CFU/mL。定量分析表明 LOD 为 10 CFU/mL。固定的“末端”Lis-mAb-NH-TEG-AuNPs LFS 与其他病原菌没有交叉反应，并且在不同的食品基质（包括人血液、牛奶和蘑菇样品）中具有实际性能。此外，使用经血液培养方法验证的 12 个临床样本评估了固定“端上”Lis-mAb-NH-TEG-AuNPs LFS 用于检测单核细胞增生李斯特菌的临床性能。它与参考方法表现出极好的一致性，没有观察到假阳性或假阴性结果。因此，固定的“端上”Lis-mAb-NH-TEG-AuNPs LFS 有望成为即时检测 (POCT) 的候选材料，能够快速、精确且高度灵敏地检测单核细胞增生李斯特菌临床样本和受污染的食品中。