On-Needle Detection of Foodborne Pathogens via Integrated Hydrogel Microneedle Array for Bacterial Capture and Recombinase Polymerase Amplification

Foodborne pathogens are one of the major factors contributing to food safety issues, necessitating the urgent development of rapid, efficient, and safe detection strategies for foodborne microorganisms. Herein, an on-needle detection platform of foodborne pathogens based on an integrated hydrogel microneedle array (MN) was developed for bacterial capture and recombinase polymerase amplification (RPA). This technology utilized MNs for rapid isolation of target bacteria and achieved on-needle detection through a preloaded RPA reaction system within the MN. Using Staphylococcus aureus (S. aureus) as a model, the proposed method enabled on-needle quantification in 30 min, achieving a limit of detection (LOD) of 3.6 CFU/g. The proposed assay exhibited good specificity for S. aureus and was successfully applied to evaluate the S. aureus contamination in commercial pork samples. Moreover, the method could be extended to detect Salmonella typhimurium (S. typhimurium) and Listeria monocytogenes (L. monocytogenes), reflecting its broad applicability. This study opens a new avenue for simplifying microbial detection processes, significantly streamlining the pretreatment workflow, and reducing detection time, thereby demonstrating broad application prospects in the field of on-site rapid detection.