Zhang Yan, Luo Feifei, Zhang Yating, Zhu Luqi, Li Yi, Zhao Shuangli, He Pingang, Wang Qingjiang
School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
J Chromatogr A. 2018 Jan 26;1534:188-194. doi: 10.1016/j.chroma.2017.12.054. Epub 2017 Dec 23.
The detection of Salmonella enterica serovar Typhimurium (S. Typhimurium) is very important for the prevention of food poisoning and other infectious diseases. Here we reported a simple and sensitive strategy to test S. Typhimurium by microchip capillary electrophoresis couple with laser-induced fluorescence (MCE-LIF) based on the specific reaction between the bacterium and corresponding aptamers. Based on the differences in charge to mass ratio between bacteria-aptamer complexes and free aptamers, a separation of the complexes and free aptamers could be obtained by MCE. The optimal parameters of the specific reaction including fluorescent dye concentration, Mg concentration, incubation time, and pH of incubation solution were carefully investigated. Meanwhile, a non-specific DNA was exploited as a contrast for the detection of S. Typhimurium. Under the optimal conditions, a rapid separation of the bacteria-aptamer complex and free aptamers was achieved within 135 s with a limit of detection (S/N = 3) of 3.37 × 10 CFU mL. This method was applied for the detection of S. Typhimurium in fresh milk samples and a recovery rate of 95.8% was obtained. The experimental results indicated that the specific aptamers are of enough biostability and the established method could be used to analyze S. Typhimurium in foods.
肠炎沙门氏菌鼠伤寒血清型（鼠伤寒沙门氏菌）的检测对于预防食物中毒和其他传染病非常重要。在此，我们报道了一种基于细菌与相应适配体之间的特异性反应，通过微芯片毛细管电泳与激光诱导荧光（MCE-LIF）联用检测鼠伤寒沙门氏菌的简单且灵敏的策略。基于细菌-适配体复合物与游离适配体之间质荷比的差异，可通过MCE实现复合物与游离适配体的分离。仔细研究了特异性反应的最佳参数，包括荧光染料浓度、镁离子浓度、孵育时间和孵育溶液的pH值。同时，利用非特异性DNA作为对照来检测鼠伤寒沙门氏菌。在最佳条件下，135秒内实现了细菌-适配体复合物与游离适配体的快速分离，检测限（S/N = 3）为3.37×10 CFU/mL。该方法应用于鲜牛奶样品中鼠伤寒沙门氏菌的检测，回收率为95.8%。实验结果表明，特异性适配体具有足够的生物稳定性，所建立的方法可用于分析食品中的鼠伤寒沙门氏菌。
