Filter-assisted sample preparation for on-site detection using a bi-functional linker-based biosensor demonstrated with Escherichia coli O157:H7.

This study presents an advanced food detection platform that integrates filter-assisted sample preparation (FASP) with a bifunctional linker-based biosensor for on-site detection of Escherichia coli O157:H7 as a model case. FASP isolates bacteria from food samples through multi-filter preprocessing, significantly enhancing the specificity, sensitivity, and reproducibility of the subsequent biosensor analysis. This platform can detect E. coli O157:H7 at concentrations as low as 10 CFU per 25 g of tomato with a total processing time of 2.5 h from sampling to testing using an on or off detection method. FASP supports large food processing volumes up to 250 mL, maximizing bacterial capture and minimizing microbial loss during pre-treatment. This integrated approach significantly improves the speed, accuracy, and practicality of pathogen detection, offering a robust solution for onsite microbial detection and enhancing food safety monitoring in the food industry.