CRISPR/Cas12a gene editing system combined with hairpin DNA for E. coli-2571 detection by electrochemical biosensor

The human gastrointestinal system contains the conditional pathogen Escherichia coli ( E. coli ), which is a significant cause of vomiting and diarrhea—both of which can be fatal in extreme cases. Given the surge in hospital infections and water pollution, the development of early detection and diagnosis procedures is imperative. This study proposes an electrochemical biosensor for E. coli detection, utilizing nucleic acid aptamers as recognition elements and using E. coli-2571 as an example. It is based on the CRISPR/Cas gene-editing technology. Specifically, the collateral cleavage activity of Cas12a shifts the electrochemical signal after loading the DNA sequence tagged with an electrochemical signal onto the gold electrode, which ultimately enables the identification of E. coli . The biosensor has a detection limit of 13.1 CFU/mL and exhibits a good linear relationship in the concentration range of 10 2 ––10 7 CFU/mL. It was effectively used for the quantitative detection of E. coli in milk and pure water, with a recovery rate ranging from 93.12 % to 98.93 %. The biosensor offers a rapid, precise, affordable, and sensitive tool for E. coli detection. It is anticipated to become a powerful instrument for identifying microorganisms that pose a risk to public health and human health.