Çam Dilek, Öktem Hüseyin Avni
Department of Biological Sciences, Middle East Technical University , Ankara , Turkey.
Department of Biology, Çankırı Karatekin University , Çankırı , Turkey.
Turk J Biol. 2017 Dec 18;41(6):954-968. doi: 10.3906/biy-1705-50. eCollection 2017.
Lateral flow assay (LFA), or the immunochromatographic strip test, is popular to use for rapid and sensitive immunoassays. Gold nanoparticles (GNPs), due to tunable optical characteristics and easy manipulation of size or shape, represent an attractive approach for LFA technology. Since most enterohemorrhagic infections result from water and food contaminations of Escherichia coli O157:H7, selective and rapid detection of this organism in environmental and biological complexes is necessary. In this study, optimized parameters of antibody (Ab)-based LFA for rapid detection of pathogenic E. coli O157:H7 are described. GNPs were used as visualizing agents. The measuring parameters include the Ab concentration on the capture lines, the concentration of gold conjugate, and flow rate. M180 and 36 nm were the ideal membrane and GNP size, respectively, for bacterial detection of LFA. The target, E. coli O157:H7, could be detected with a visual limit of detection of 105 cfu/mL in 3-5 min. Selectivity of the system was very high and the target was recognized by developed strips, regardless of its presence singly or in mixed bacterial samples.
侧向流动分析（LFA），即免疫层析试纸条检测，常用于快速灵敏的免疫分析。金纳米颗粒（GNPs）由于具有可调节的光学特性且易于控制尺寸或形状，是LFA技术中一种有吸引力的方法。由于大多数肠出血性感染是由大肠杆菌O157:H7污染水和食物引起的，因此在环境和生物复合物中选择性快速检测这种细菌很有必要。在本研究中，描述了基于抗体（Ab）的LFA快速检测致病性大肠杆菌O157:H7的优化参数。金纳米颗粒用作可视化试剂。测量参数包括捕获线上抗体的浓度、金偶联物的浓度和流速。对于LFA的细菌检测，M180和36 nm分别是理想的膜和金纳米颗粒尺寸。目标菌大肠杆菌O157:H7在3 - 5分钟内的可视检测限为105 cfu/mL。该系统的选择性非常高，无论目标菌单独存在还是存在于混合细菌样本中，所开发的试纸条都能识别。
