Self-protective DNAzyme-based dual-responsive three-way Y-probe for simultaneous determination of multiple pathogenic bacteria.

Foodborne pathogens, a major cause of foodborne illness due to their high virulence, pose a serious threat to public health. Consequently, identification of foodborne pathogens is essential for the prevention and treatment of foodborne infections. Consequently, there is an immediate need to establish a highly specific and precise approach for the concurrent detection of several foodborne pathogens. Herein, we developed a DNAzyme-based self-protecting dual-response nanoprobe for the simultaneous detection of two foodborne pathogens. The technique utilizes nanostructures to achieve logical signal input and output. In the presence of the target pathogen, the pathogen binds to the arch probe and releases the activation chain, which in turn activates a strand-displacement reaction and DNAzyme for signal amplification, producing different output signals to complete the simultaneous detection of multiple pathogens. The limits of detection for E. coli O157:H7 and S. typhimurium were determined to be 3.7 cfu/mL and 3.2 cfu/mL, with a measurement response time of 2 h. This approach enables ultrasensitive, specific, and simultaneous detection of two foodborne pathogens and is applicable for identifying foodborne pathogens in actual biological samples. The fluorescence detection of foodborne pathogens with a three-way Y-probe and DNAzyme coupling represents a novel approach for the concurrent identification of several foodborne diseases.