High-performance electrochemical biosensor comprising Mn-ZIF-67 conjugated with anti-O antibody for Escherichia coli detection

The detection of Escherichia coli ( E. coli ) in food and water is critical for public health, yet existing methods often lack sensitivity, speed, or field applicability. Here, we develop an electrochemical biosensor based on Mn-doped Co zeolitic imidazolate framework (ZIF-67) functionalized with anti-O antibody for sensitive E. coli detection. Mn incorporation induces phase reconstruction, surface area enhancement, and electron transfer. Antibody conjugation modulates wettability, introduces amide I and II vibrational modes, and selectively blocks electron transfer upon bacterial binding. The biosensor exhibits a linear range of 10 to 10 10 CFU mL –1 with a 1 CFU mL –1 detection limit, outperforming optical and other metal organic framework-based sensors. It can discriminate non-target bacteria ( Salmonella, Pseudomonas aeruginosa, Staphylococcus aureus ), maintain >80% sensitivity over 5 weeks, and recover 93.10 –107.52% E. coli spiked in tap water. This work suggests the tremendous potential for on-site pathogen monitoring.