Foodborne pathogens such as Escherichia coli O157:H7 (E. coli O157:H7) pose a serious global health threat, thus, the high cost and operational complexity of the conventional detection methods have driven the development of rapid, sensitive, and portable diagnostic platforms. In this study, we developed a colorimetric biosensor for the rapid detection of E. coli O157:H7. The biosensor utilized a dual-aptamers recognition probe that specifically bound to E. coli O157:H7, triggering a non-enzyme signal amplification strategy that generated G-quadruplex (G4) fragments. These G4 fragments then facilitated the formation of a DNAzyme complex in the presence of Hemin which exhibited horseradish peroxidase (HRP)-mimicking activity, catalyzing the oxidation of a chromogen substrate and producing a visible colorimetric signal. The assay demonstrated a broad dynamic range from 2 to 107 CFU/mL with an ultra low limit of detection (LOD) of 11 CFU in 10 mL, ensuring highly sensitive and selective detection, even in complex sample matrices. Notably, the colorimetric signal could be easily analyzed using a smartphone, displaying excellent linearity and enabling point-of-care testing (POCT). Overall, the developed assay demonstrated high specificity, cost-effectiveness, and portability, making it a promising tool for on-site food safety monitoring and public health surveillance.
扫码关注我们
求助内容:
应助结果提醒方式:
