基于树枝状金纳米粒子的双模免疫层析分析用于超灵敏检测大肠杆菌 O157:H7 的荧光猝灭。

Dual-mode immunochromatographic assay based on dendritic gold nanoparticles with superior fluorescence quenching for ultrasensitive detection of E. coli O157:H7.

机构信息

Department of Food Science and Engineering, Institute of Food Safety and Nutrition, College of Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Agricultural Microbiomics and Precision Application, Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.

出版信息

Food Chem. 2023 Oct 30;424:136366. doi: 10.1016/j.foodchem.2023.136366. Epub 2023 May 13.

DOI:10.1016/j.foodchem.2023.136366

PMID:37201472

Abstract

We presented a colorimetric/fluorescent dual-mode immunochromatographic assay (ICA) for the sensitive detection of Escherichia coli O157:H7. The use of polydopamine (PDA)-modified gold nanoparticles (AuNPs) with broadband absorption allowed for excellent colorimetry signals for the ICA detection. Moreover, the absorption spectrum of PDA-AuNPs significantly overlaps with the excitation and emission spectra of ZnCdSe/ZnS quantum dots (QDs), resulting in effective quenching of the QDs fluorescence due to the inner filter effect. The fluorescence intensity changes induced by PDA-AuNPs were utilized for the sensitive detection of E. coli O157:H7, achieving a detection limit of 9.06 × 10 CFU/mL, which was 46-fold lower than that of traditional AuNPs-based immunoassay. The proposed immunosensor exhibited the recovery rate between 80.12% and 114.69% in detecting actual samples, indicating its reliability and satisfactory accuracy. This study provides insights into dual-mode signal outputs and the ICA development for food safety applications.

摘要

我们提出了一种用于灵敏检测大肠杆菌 O157:H7 的比色/荧光双模免疫层析分析（ICA）方法。使用具有宽带吸收的聚多巴胺（PDA）修饰的金纳米粒子（AuNPs）可获得出色的 ICA 检测比色信号。此外，PDA-AuNPs 的吸收光谱与 ZnCdSe/ZnS 量子点（QDs）的激发和发射光谱显著重叠，由于内滤效应，导致 QDs 荧光有效猝灭。利用 PDA-AuNPs 引起的荧光强度变化来灵敏检测大肠杆菌 O157:H7，检测限达到 9.06×10 CFU/mL，比传统的基于 AuNPs 的免疫分析低 46 倍。在检测实际样品时，所提出的免疫传感器的回收率在 80.12%至 114.69%之间，表明其可靠性和令人满意的准确性。本研究为食品安全应用中的双模信号输出和 ICA 发展提供了思路。