Universal biosensing platform based on polyMn-MOF nanosheets for efficient analysis of foodborne pathogens from...

A universal electrochemical aptasensing strategy was developed for sensitive detection of various pathogenic bacteria (such as Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella enterica) that commonly existed in food products. Diverse categories of pathogenic bacterium-targeting aptamers were separately immobilized over the polyMOF, which was prepared using the polyether polymer ligand containing 1,4-benzenedicarboxylic acid (polyH₂bdc) units as building block, 4,4'-bipyridine as co-ligand, polyvinyl pyrrolidone as structural regulator, and MnCl₂ as metal centers (represented by polyMn-MOF). The developed polyMn-MOF-based aptasensor illustrated ultralow limits of detection for three kinds of foodborne pathogens (2.6, 1.5, and 3.5 CFU mL^-1 for SE, S. aureus, and E. coli, respectively) in a wide linear range of 10 - 1 × 10⁸ CFU mL^-1 of pathogenic bacteria concentration by differential pulse voltammetry, accompanying with high selectivity, good stability, and superior reproducibility. Considering these advantages, the fabricated polyMOF-based aptasensor demonstrated wide applications in food safety and analysis and other biosensing fields.