Abstract：
Bacterial infection is a great threat to human health. Lateral flow immunoassays (LFIAs) with the merits of low cost, quick screening, and on-site detection are competitive technologies for bacteria detection, but their detection limits depend on the optical performance of the adopted nanotags. Herein, we presented a LFIA platform for bacteria detection using polydopamine (PDA) functionalized Au nanoparticles (denoted as Au@PDA) as the nanotag. The introduction of PDA could provide enhanced light absorption of Au, as well as numerous functional groups for conjugation. Small recognition molecules i.e. vancomycin (Van) and p-mercaptophenylboronic acid (PMBA) were covalently anchored to Au@PDA, and selected as the specific probes towards Gram-positive (G+) and Gram-negative (G-) bacteria, respectively. Taken Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as the representative targets of G+ and G- bacteria, two LFA strips were successfully constructed based on the immuno-sandwich principle. They could quantitatively detect S. aureus and E. coli both down to 102 cfu/mL, a very competitive detection limit in comparison with other colorimetric or luminescent probes-based LFIAs. Furthermore, the proposed two strips were applied for the quantitative, accurate, and rapid detection of S. aureus and E. coli in food and human urine samples with good analytical results obtained. In addition, they were integrated as a screening platform for quick evaluation of diverse antibacterial agents within 3 h, which is remarkably shortened compared with that of the two traditional methods i.e. bacterial culture and plate-counting.
摘要：
细菌感染对人类健康构成巨大威胁。侧流免疫测定(LFIA)具有低成本的优点，快速筛选,现场检测是细菌检测的竞争性技术，但是它们的检测限取决于所采用的纳米标签的光学性能。在这里，我们提出了使用聚多巴胺（PDA）功能化的Au纳米颗粒（表示为Au@PDA）作为纳米标签进行细菌检测的LFIA平台。PDA的引入可以增强Au的光吸收，以及许多用于共轭的官能团。小识别分子，即万古霉素（Van）和对巯基苯基硼酸（PMBA）共价锚定在Au@PDA上，并选择作为针对革兰氏阳性（G+）和革兰氏阴性（G-）细菌的特异性探针，分别。服用金黄色葡萄球菌(S.金黄色葡萄球菌)和大肠杆菌(E.大肠杆菌)作为G+和G-细菌的代表靶标，基于免疫夹心原理成功构建了两个LFA条。他们可以定量检测金黄色葡萄球菌和大肠杆菌都低至102cfu/mL，与其他基于比色或发光探针的LFIA相比，这是一个非常有竞争力的检测限。此外，提出的两个条带用于定量，准确,并快速检测食品和人体尿液样品中的金黄色葡萄球菌和大肠杆菌，获得了良好的分析结果。此外,它们被整合为一个筛选平台，在3小时内快速评估各种抗菌剂，与细菌培养和平板计数两种传统方法相比，明显缩短。
