In this study, we successfully developed a simple and rapid method for simultaneous detection of Salmonella spp., Listeria monocytogenes, and Escherichia coli using gold nanoparticles and the aptamer aptasensor. We screened 25 specific DNA aptamer candidates against these pathogens using whole-cell Systematic Evolution of Ligands by EXponential enrichment. Among them, Ap6 was selected due to its low energy minimization values of −12.25 and −27.67 kcal/mol derived from MFold and RNAFold analysis, respectively. The assay presented in this study allowed the visual colorimetric detection of labeled colloidal gold nanoparticles as well as determination of UV absorbance at 625 and 525 nm under optimized conditions. The detection limit of this aptasensor was as less as 105 CFU/ml. A random investigation of 50 meat samples, including ham and chicken sausages, collected from the local market revealed 96% accuracy, 96% specificity, and 100% sensitivity of the assay. The colorimetric aptasensor can accomplish one-step detection without pre-culture, DNA extraction, and amplification. Hence, it is an easy, rapid, specific, and qualitative assay that can be used as a point-of-care testing to directly detect multiplex foodborne pathogens.

中文翻译：

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用于检测肉类样品中的沙门氏菌、单核细胞增生李斯特菌和大肠杆菌的比色适体传感器

在本研究中，我们成功开发了一种使用金纳米粒子和适体适体传感器同时检测沙门氏菌属、单核细胞增生李斯特氏菌和大肠杆菌的简单快速方法。我们通过指数富集使用配体的全细胞系统进化筛选了 25 种针对这些病原体的特定 DNA 适配子候选物。其中，选择 Ap6 是因为其能量最小化值分别为 -12.25 和 -27.67 kcal/mol，分别来自 MFold 和 RNAFold 分析。本研究中提出的测定允许对标记的胶体金纳米粒子进行目视比色检测，并在优化条件下测定 625 和 525 nm 处的紫外吸光度。该适体传感器的检测限低至 105 CFU/ml。随机调查 50 个肉类样品，包括从当地市场收集的火腿和鸡肉香肠，显示该测定的准确度为 96%，特异性为 96%，灵敏度为 100%。比色适体传感器无需预培养、DNA提取和扩增即可完成一步检测。因此，它是一种简单、快速、特异性和定性的检测方法，可用作即时检测以直接检测多重食源性病原体。