Abstract：
BACKGROUND: Rapid and sensitive detection of foodborne pathogens in food plays a crucial role in controlling outbreaks of foodborne diseases, of which Listeria monocytogenes and Salmonella typhimurium are representative and notable pathogens. Thus, it\'s of great importance to achieve the effective detection of these pathogens. However, the most common detection methods (culture-based technique, Polymerase Chain Reaction and immunological methods) have disadvantages that cannot be ignored, such as time-consuming, laborious, complex sample preparation process, and the possibility of cross-reaction. Hence, it is essential to develop a facile detection method for the pathogens with high sensitivity and specificity to avoid the above-mentioned disadvantages.
RESULTS: We report a label-free visual platform for the simultaneous capture and detection of Listeria monocytogenes and Salmonella typhimurium. For the first time, we have prepared polydimethylsiloxane-Chromotrope 2R membrane which serves as the substrate for bacterial capture and enrichment through the formation of specific recognition sites. The positively charged Pt-covalent organic framework combines with the pathogens through surface charge interaction, thereby the label-free sandwich platform is formed. Remarkable peroxidase activity of Pt-covalent organic framework converts the conversion of bacterial quantity into amplified color signal by catalyzing 3,3\',5,5\'-Tetramethylbenzidine to oxidized 3,3\',5,5\'-Tetramethylbenzidine. The platform demonstrates the capability to identify two representative food-borne pathogens within a time frame of 100 min, exhibiting high sensitivity and excellent specificity without the interference from non-target bacteria. The limit of detection of the visual platform toward Listeria monocytogenes and Salmonella typhimurium was 1.61 CFU mL-1 and 1.31 CFU mL-1, respectively. And the limit of quantification toward Listeria monocytogenes and Salmonella typhimurium was 4.94 CFU mL-1 and 2.47 CFU mL-1, respectively. The relative standard derivations of the visual platform for both bacteria were lower than 4.9 %. Furthermore, our proposed platform has obtained reliable and satisfactory results on analyzing diverse food samples.
CONCLUSIONS: This research expands the application of a label-free platform combined with unlabeled nanocomponents in the rapid isolation and detection of diverse of food-borne pathogens. The platform possesses the advantages of simple operation and real-time monitoring, without complicated sample pretreatment process. The whole detection process can realize the simultaneous monitoring of Listeria monocytogenes and Salmonella typhimurium within 100 min. Furthermore, it is also of reference significance for the detection of other common pathogens.
RESULTS: We report a label-free visual platform for the simultaneous capture and detection of Listeria monocytogenes and Salmonella typhimurium. For the first time, we have prepared polydimethylsiloxane-Chromotrope 2R membrane which serves as the substrate for bacterial capture and enrichment through the formation of specific recognition sites. The positively charged Pt-covalent organic framework combines with the pathogens through surface charge interaction, thereby the label-free sandwich platform is formed. Remarkable peroxidase activity of Pt-covalent organic framework converts the conversion of bacterial quantity into amplified color signal by catalyzing 3,3\',5,5\'-Tetramethylbenzidine to oxidized 3,3\',5,5\'-Tetramethylbenzidine. The platform demonstrates the capability to identify two representative food-borne pathogens within a time frame of 100 min, exhibiting high sensitivity and excellent specificity without the interference from non-target bacteria. The limit of detection of the visual platform toward Listeria monocytogenes and Salmonella typhimurium was 1.61 CFU mL-1 and 1.31 CFU mL-1, respectively. And the limit of quantification toward Listeria monocytogenes and Salmonella typhimurium was 4.94 CFU mL-1 and 2.47 CFU mL-1, respectively. The relative standard derivations of the visual platform for both bacteria were lower than 4.9 %. Furthermore, our proposed platform has obtained reliable and satisfactory results on analyzing diverse food samples.
CONCLUSIONS: This research expands the application of a label-free platform combined with unlabeled nanocomponents in the rapid isolation and detection of diverse of food-borne pathogens. The platform possesses the advantages of simple operation and real-time monitoring, without complicated sample pretreatment process. The whole detection process can realize the simultaneous monitoring of Listeria monocytogenes and Salmonella typhimurium within 100 min. Furthermore, it is also of reference significance for the detection of other common pathogens.
摘要：
背景：快速，灵敏地检测食品中的食源性病原体在控制食源性疾病的暴发中起着至关重要的作用。其中单核细胞增生李斯特菌和鼠伤寒沙门氏菌是代表性和值得注意的病原体。因此，实现对这些病原体的有效检测具有重要意义。然而,最常见的检测方法(基于培养的技术，聚合酶链反应和免疫学方法）具有不可忽视的缺点，例如耗时，辛苦,复杂的样品制备过程，以及交叉反应的可能性。因此，为了避免上述缺点，有必要开发一种高灵敏度和特异性的病原体检测方法。
结果：我们报告了一个无标签的可视化平台，用于同时捕获和检测单核细胞增生李斯特菌和鼠伤寒沙门氏菌。第一次,我们已经制备了聚二甲基硅氧烷-Chromotrope2R膜，该膜通过形成特定的识别位点作为细菌捕获和富集的底物。带正电荷的Pt共价有机骨架通过表面电荷相互作用与病原体结合，从而形成无标签夹层平台。Pt共价有机骨架的显著过氧化物酶活性通过催化3,3\'将细菌数量的转化转化为放大的颜色信号,5,5'-四甲基联苯胺氧化至3,3'，5,5'-四甲基联苯胺。该平台展示了在100分钟的时间范围内识别两种代表性食源性病原体的能力，在不受非靶标细菌干扰的情况下，表现出高灵敏度和优异的特异性。视觉平台对单核细胞增生李斯特菌和鼠伤寒沙门氏菌的检测极限分别为1.61CFUmL-1和1.31CFUmL-1。单核细胞增生李斯特菌和鼠伤寒沙门氏菌的定量限分别为4.94CFUmL-1和2.47CFUmL-1。两种细菌的视觉平台的相对标准导数低于4.9%。此外，我们提出的平台在分析各种食品样品方面获得了可靠和令人满意的结果。
结论：这项研究扩展了无标签平台与未标记的纳米组分结合在快速分离和检测各种食源性病原体中的应用。该平台具有操作简单、实时监控等优点,无需复杂的样品预处理过程。整个检测过程可在100min内实现单核细胞增生李斯特菌和鼠伤寒沙门氏菌的同时监测。此外，对其他常见病原体的检测也有借鉴意义。
结果：我们报告了一个无标签的可视化平台，用于同时捕获和检测单核细胞增生李斯特菌和鼠伤寒沙门氏菌。第一次,我们已经制备了聚二甲基硅氧烷-Chromotrope2R膜，该膜通过形成特定的识别位点作为细菌捕获和富集的底物。带正电荷的Pt共价有机骨架通过表面电荷相互作用与病原体结合，从而形成无标签夹层平台。Pt共价有机骨架的显著过氧化物酶活性通过催化3,3\'将细菌数量的转化转化为放大的颜色信号,5,5'-四甲基联苯胺氧化至3,3'，5,5'-四甲基联苯胺。该平台展示了在100分钟的时间范围内识别两种代表性食源性病原体的能力，在不受非靶标细菌干扰的情况下，表现出高灵敏度和优异的特异性。视觉平台对单核细胞增生李斯特菌和鼠伤寒沙门氏菌的检测极限分别为1.61CFUmL-1和1.31CFUmL-1。单核细胞增生李斯特菌和鼠伤寒沙门氏菌的定量限分别为4.94CFUmL-1和2.47CFUmL-1。两种细菌的视觉平台的相对标准导数低于4.9%。此外，我们提出的平台在分析各种食品样品方面获得了可靠和令人满意的结果。
结论：这项研究扩展了无标签平台与未标记的纳米组分结合在快速分离和检测各种食源性病原体中的应用。该平台具有操作简单、实时监控等优点,无需复杂的样品预处理过程。整个检测过程可在100min内实现单核细胞增生李斯特菌和鼠伤寒沙门氏菌的同时监测。此外，对其他常见病原体的检测也有借鉴意义。
