Hu Wenjin, Wang Shengyang, Du Qing, Yang Shixiang, Wei Xiaxia, Li Xi, Lin Huai
Precision Medicine Translational Research Center, West China Hospital, Sichuan University, Chengdu, 610213, China.
State Key Laboratory of Water Pollution Control and Green Resource Recycling, School of the Environment, Nanjing University, Nanjing, 210093, China.
Anal Chim Acta. 2025 Oct 1;1369:344360. doi: 10.1016/j.aca.2025.344360. Epub 2025 Jun 25.
Foodborne pathogen contamination represents a critical global public health challenge. Lateral flow immunoassay (LFIA) has emerged as an indispensable analytical platform for point-of-care detection of pathogenic microorganisms. Nevertheless, conventional dual-monoclonal antibody-based sandwich formats suffer from intrinsic sensitivity limitations that restrict their detection applications. To address this critical challenge, we present an innovative dual-signal amplified LFIA (D-LFIA) platform integrating nanobody-engineered magnetic quantum dot nanocomposites for simultaneous ultrasensitive detection of three high-risk foodborne pathogens: Salmonella enteritidis, Listeria monocytogenes, and Campylobacter jejuni.
Specifically, we engineered a dual-functional detection system by incorporating nanobodies into traditional antibody pairs and conjugating them with a triphasic core-shell-satellite architecture nanocomposites, which serve as enrichment-detection dual-functional tags. Our optimized D-LFIA system demonstrated excellent analytical performance, with detection limits of 38, 125, and 47 CFU/mL for the respective pathogens-representing a 32- to 54.9-fold improvement over conventional single-probe LFIA. The multiplex detection capability was successfully demonstrated through simultaneous identification of all three pathogens within 13 min. Validation studies confirmed excellent selectivity, stability, accuracy, and repeatability, with the ability to detect as low as 5 cfu of each pathogen within 2.0-6.5 h.
The developed D-LFIA platform significantly advances field-deployable diagnostics, offering transformative potential for food safety monitoring and public health emergency responses. This nanotechnology-integrated approach provides a versatile framework that could be readily adapted for detecting other microbial contaminants through modular probe redesign.
食源性病原体污染是一项严峻的全球公共卫生挑战。侧向流动免疫分析（LFIA）已成为即时检测致病微生物不可或缺的分析平台。然而，传统的基于双单克隆抗体的夹心形式存在内在的灵敏度限制，制约了其检测应用。为应对这一关键挑战，我们提出了一种创新的双信号放大LFIA（D-LFIA）平台，该平台集成了纳米抗体工程化的磁性量子点纳米复合材料，用于同时超灵敏检测三种高风险食源性病原体：肠炎沙门氏菌、单核细胞增生李斯特菌和空肠弯曲菌。
具体而言，我们通过将纳米抗体纳入传统抗体对并将其与三相核壳卫星结构纳米复合材料偶联，构建了一个双功能检测系统，该纳米复合材料用作富集-检测双功能标签。我们优化后的D-LFIA系统展现出优异的分析性能，对各病原体的检测限分别为38、125和47 CFU/mL，相较于传统单探针LFIA提高了32至54.9倍。通过在13分钟内同时鉴定所有三种病原体，成功展示了多重检测能力。验证研究证实了其具有出色的选择性、稳定性、准确性和可重复性，能够在2.0至6.5小时内检测低至5 cfu的每种病原体。
所开发的D-LFIA平台显著推进了可现场部署的诊断技术，为食品安全监测和公共卫生应急响应提供了变革性潜力。这种纳米技术集成方法提供了一个通用框架，可通过模块化探针重新设计轻松适用于检测其他微生物污染物。
