School of Natural Resources, The University of Tennessee Institute of Agriculture, Knoxville, TN, USA.
Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
Sci Rep. 2024 Nov 22;14(1):28942. doi: 10.1038/s41598-024-80392-4.
Foodborne bacteria like Escherichia coli threaten global food security, necessitating affordable, on-site detection methods, especially in resource-limited settings. This study optimized loop-mediated isothermal amplification (LAMP) integrated with peroxidase-mimicking G-quadruplex DNA structures (DNAzyme), termed DNAzyme-LAMP which was designed to incorporate two different catalytic DNAzymes per amplification unit, enabling colorimetric detection of E. coli in leafy vegetables and milk samples. Additionally, we introduce a novel electrochemical method that enhances analytical sensitivity. The optimized DNAzyme-LAMP achieved a detection limit below 6.3 CFU per reaction or 0.1 aM gene copies. This system lays the groundwork for the development of on-site biosensors and can be adapted for detecting other foodborne pathogens.
食源性病原体如大肠杆菌威胁着全球粮食安全，需要经济实惠、现场可用的检测方法，特别是在资源有限的环境中。本研究优化了环介导等温扩增（LAMP）与过氧化物酶模拟 G-四链体 DNA 结构（DNAzyme）的结合，称之为 DNAzyme-LAMP，它被设计成在每个扩增单元中包含两个不同的催化 DNAzyme，从而实现对叶类蔬菜和牛奶样本中大肠杆菌的比色检测。此外，我们引入了一种新颖的电化学方法来提高分析灵敏度。优化后的 DNAzyme-LAMP 的检测限低于每反应 6.3 CFU 或 0.1 aM 基因拷贝。该系统为现场生物传感器的开发奠定了基础，并且可以适应于检测其他食源性病原体。
