Thiol-ene click reaction aptamer sensor based on MWCNT-COOH/MOF-818 composite for highly sensitive detection of foodborne pathogenic bacteria

This study established a unified electrochemical sensing platform for the ultra-sensitive and rapid detection of foodborne pathogens. Targeting three representative pathogenic bacteria— Staphylococcus aureus , Escherichia coli , and Salmonella typhimurium —a composite sensing interface was fabricated by integrating MWCNT-COOH with MOF-818. Highly specific aptamers were directionally immobilized onto the MWCNT-COOH/MOF-818 composite surface through thiol-ene click chemistry, yielding an electrochemical biosensor with superior performance. Experimental results revealed detection limits of 3, 6, and 4 CFU mL −1 for the three target bacteria, respectively. Moreover, the sensor displayed strong detection capabilities in authentic food samples (pork paste). This detection strategy by integrating sample recognition and signal transduction within a single interface can be generalized to multiple pathogens via aptamer substitution, offering a novel technical approach for on-site rapid screening in food safety. This platform holds considerable potential for the prevention and control of foodborne diseases.