A Collection of RPA-Based Photoelectrochemical Assays for the Portable Detection of Multiple Pathogens

Portable, ultrasensitive, and simultaneously quantitative detection of the nucleic acids of multiple foodborne pathogens is critical to public health. However, the current testing methods depend on costly equipment and tedious amplification steps. In this study, we propose a photoelectrochemical (PEC) biosensor combined with recombinase polymerase amplification (RPA) technology (RPA-PEC) for the rapid detection of multiple foodborne pathogens under irradiation of 980 nm light. In particular, two working surfaces were designed on homemade three-dimensional screen-printed paper-based electrodes. The genomic DNAs of Escherichia coli O157:H7 and Staphylococcus aureus was initiated by RPA on the corresponding electrode surfaces, thus forming a lab-on-paper platform. Using the formed DNA-PEC signaler, photocurrents were achieved at 37 °C after only 20 min of RPA. The detection performance was superior to that of conventional agarose gel electrophoresis, with detection limits of 3.0 and 7.0 copies/μL for E. coli O157:H7 and S. aureus, respectively. Our study pioneers a new RPA-PEC method for foodborne pathogens and provides directions for the construction of lab-on-paper platforms for the portable detection of multiple nucleic acids.