Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907-2009, USA.
J Appl Microbiol. 2010 Sep;109(3):808-17. doi: 10.1111/j.1365-2672.2010.04709.x.
To develop antibody-aptamer functionalized fibre-optic biosensor for specific detection of Listeria monocytogenes from food products.
Aptamer, a single-stranded oligonucleotide ligand that displays affinity for the target molecule, was used in the assay to provide sensor specificity. Aptamer-A8, specific for internalin A, an invasive protein of L. monocytogenes, was used in the fibre-optic sensor together with antibody in a sandwich format for detection of L. monocytogenes from food. Biotinylated polyclonal anti-Listeria antibody, P66, was immobilized on streptavidin-coated optical waveguide surface for capturing bacteria, and Alexa Fluor 647-conjugated A8 was used as a reporter. The biosensor was able to selectively detect pathogenic Listeria in pure culture and in mixture with other bacteria at a concentration of approx. 10(3) CFU ml(-1). This sensor also successfully detected L. monocytogenes cells from artificially contaminated (initial inoculation of 10(2) CFU 25 g(-1) ) ready-to-eat meat products such as sliced beef, chicken and turkey after 18 h of enrichment.
Based on the data presented in this study, the antibody-aptamer functionalized fibre-optic biosensor could be used as a detection tool for sensitive and specific detection of L. monocytogenes from foods.
The study demonstrates feasibility and novel application of aptamer on fibre-optic biosensor platform for the sensitive detection of L. monocytogenes from food products.
开发抗体-适体功能化光纤生物传感器，用于特异性检测食品中的单核细胞增生李斯特菌。
适体是一种单链寡核苷酸配体，对靶分子具有亲和力，在测定中用于提供传感器的特异性。适体 A8 特异性针对李斯特菌的侵袭蛋白内毒素 A，与抗体一起用于光纤传感器中，以夹心形式检测食品中的李斯特菌。生物素化多克隆抗李斯特菌抗体 P66 固定在链霉亲和素涂覆的光波导表面上用于捕获细菌，并用 Alexa Fluor 647 标记的 A8 作为报告分子。该生物传感器能够选择性地检测纯培养和与其他细菌混合培养的致病性李斯特菌，浓度约为 10(3) CFU ml(-1)。该传感器还成功地从人工污染（初始接种 10(2) CFU 25 g(-1)）的即食肉类产品（如切片牛肉、鸡肉和火鸡肉）中检测到单核细胞增生李斯特菌细胞，经过 18 小时的富集。
基于本研究提供的数据，抗体-适体功能化光纤生物传感器可用于从食品中敏感和特异性检测单核细胞增生李斯特菌。
本研究证明了适体在光纤生物传感器平台上用于从食品中敏感检测单核细胞增生李斯特菌的可行性和新颖应用。
