Phage-Loaded Microfluidic Device for Selective Bacterium Detection with a High Potential for in-the-Field...

Detection of foodborne bacteria is critical because these pathogens cause foodborne outbreaks, which is a major public health concern worldwide. Conventional microbiological methods include plating and colony counting, molecular techniques such as polymerase chain reaction (PCR), and enzyme-linked immunosorbent assays (ELISA). These methods can be quite sensitive and specific, but they are also slow, require labor work, and often involve complex sample preparation. These limitations drive the development of faster and point-of-use detection techniques. In this study, we present a microfluidic biosensor platform based on P22 bacteriophage-loaded PDMS surfaces for rapid detection of Salmonella enterica. The PDMS surface had microscale topographical roughness, which helps improve immobilized phage concentration and promotes their capabilities to capture target bacteria. The system allows rapid bacteria detection with an experimentally demonstrated limit of detection of 9.15 × 10³ cells/mL and a demonstrated specificity for Salmonella enterica over Staphylococcus aureus employed as a non-target control. Such detection was achieved under continuous flow conditions without the need of incubation, which implies its high potential for in-field applications and in resource-limited locations. This work demonstrates a rapid and selective approach for bacterial detection with strong potential for real-world food and water safety applications.