School of Life Sciences, Shanghai University, Shanghai 200444, China.
Shanghai Customs, Shanghai 200135, China.
Food Chem. 2021 Oct 1;358:129894. doi: 10.1016/j.foodchem.2021.129894. Epub 2021 Apr 19.
Listeria monocytogenes is an important foodborne pathogen, which imposes great burdens on public health. The current methods for detecting L. monocytogene are limited in several ways such as time consuming and lab equipment dependent. In this study, we developed a new electrochemical assay to improve the efficacy. This assay allows us to generate numerous G-quadruplex sequences while loop-mediated isothermal amplification happens. Then, these G-quadruplex sequences form DNAzyme to produce a color change and an electrochemical signal by oxidizing tetramethylbenzidine. This assay could be finished in 2 h, which significantly reduced the detection time. Also, we confirmed the limit of detection of this assay at 6.8 CFU/mL according to 3σ criterion. Our assay shows good sensitivity to detect bacteria range from 52.5 to 5.25 × 10 CFU/mL. This assay's reliability was also confirmed by detecting artificially contaminated pork samples. Thus, we propose this electrochemical assay for rapid and sensitive detection of L. monocytogenes in food.
李斯特菌是一种重要的食源性致病菌，对公共健康造成了巨大负担。目前检测李斯特菌的方法在多个方面存在局限性，例如耗时且依赖实验室设备。在这项研究中，我们开发了一种新的电化学检测方法来提高检测效果。该方法在环介导等温扩增的过程中生成大量的 G-四链体序列。然后，这些 G-四链体序列形成 DNA 酶，通过氧化四甲基联苯胺产生颜色变化和电化学信号。该检测方法可在 2 小时内完成，大大缩短了检测时间。此外，根据 3σ 准则，我们确定该检测方法的检测限为 6.8 CFU/mL。该检测方法对 52.5 至 5.25×10 CFU/mL 范围内的细菌具有良好的灵敏度。通过检测人工污染的猪肉样品也证实了该检测方法的可靠性。因此，我们提出了这种用于快速灵敏检测食品中李斯特菌的电化学检测方法。
