Hahn Jungwoo, Kim Eunghee, You Young Sang, Gunasekaran Sundaram, Lim Seokwon, Choi Young Jin
Dept. of Agricultural Biotechnology, Seoul National Univ., 1 Gwanakro, Gwanakgu, Seoul 151-921, Korea.
Dept. of Biological System Engineering, Univ. of Wisconsin-Madison, Madison, Wis. 53706, U.S.A.
J Food Sci. 2017 Oct;82(10):2321-2328. doi: 10.1111/1750-3841.13861. Epub 2017 Sep 6.
On-site detection for sensitive identification of foodborne pathogens on fresh produce with minimal use of specialized instrumentation is crucial to the food industry. A switchable linker (SL)-based immunoassay was designed for ultrasensitive on-site detection of Salmonella in tomato samples. The assay is based on large-scale aggregation of gold nanoparticles (GNPs), induced by a quantitative relationship among the biotinylated Salmonella polyclonal antibody (b-Ab) used as the SL, the functionalized GNPs, and Salmonella. Important factors such as the concentration of SLs, time required for large-scale aggregation, and selectivity of b-Ab were optimized to minimize the detection time (within 45 min with gentle agitation) and achieve the lowest limit of detection (LOD; 10 CFU/g in tomato samples) possible. This SL-based immunoassay with its relatively low LOD and short detection time may meet the need for rapid, simple, on-site analysis of pathogens in fresh produce.
The novel switchable linker-based immunoassay is a rapid, specific, and sensitive method that has potential applications for routine diagnostics of Salmonella in tomato products. These advantages make it a practical approach for general use in the processing industry to detect Salmonella rapidly and to implement appropriate regulatory procedures. Furthermore, it could be applied to other fresh products including cantaloupe, strawberry, and cucumbers.
在尽量少使用专业仪器的情况下对新鲜农产品上的食源性病原体进行现场检测以实现灵敏识别，这对食品行业至关重要。设计了一种基于可切换连接子（SL）的免疫分析法，用于对番茄样品中的沙门氏菌进行超灵敏现场检测。该分析基于作为SL的生物素化沙门氏菌多克隆抗体（b-Ab）、功能化金纳米颗粒（GNP）和沙门氏菌之间的定量关系诱导的金纳米颗粒大规模聚集。对SL浓度、大规模聚集所需时间和b-Ab的选择性等重要因素进行了优化，以尽量缩短检测时间（在温和搅拌下45分钟内）并实现尽可能低的检测限（LOD；番茄样品中为10 CFU/g）。这种基于SL的免疫分析法具有相对较低的LOD和较短的检测时间，可能满足对新鲜农产品中病原体进行快速、简单现场分析的需求。
这种基于新型可切换连接子的免疫分析法是一种快速、特异且灵敏的方法，在番茄制品中沙门氏菌的常规诊断方面具有潜在应用。这些优点使其成为加工行业普遍用于快速检测沙门氏菌并实施适当监管程序的实用方法。此外，它还可应用于其他新鲜产品，包括哈密瓜、草莓和黄瓜。
