The rapid high-throughput detection of foodborne pathogens is essential in controlling food safety. In this study, a 10-channel up-converting phosphor technology-based lateral flow (TC-UPT-LF) assay was established for the rapid and simultaneous detection of 10 epidemic foodborne pathogens. Ten different single-target UPT-LF strips were developed and integrated into one TC-UPT-LF disc with optimization. Without enrichment the TC-UPT-LF assay had a detection sensitivity of 104 CFU mL−1 or 105 CFU mL−1 for each pathogen, and after sample enrichment it was 10 CFU/0.6 mg. The assay also showed good linearity, allowing quantitative detection, with a linear fitting coefficient of determination (R2) of 0.916–0.998. The 10 detection channels did not cross-react, so multiple targets could be specifically detected. When 279 real food samples were tested, the assay was highly consistent (100%) with culture-based methods. The results for 110 food samples artificially contaminated with single or multiple targets showed a high detection rate (≥80%) for most target bacteria. Overall, the TC-UPT-LF assay allows the rapid, quantitative, and simultaneous detection of 10 kinds of foodborne pathogens within 20 min, and is especially suitable for the rapid detection and surveillance of foodborne pathogens in food and water.

Upconversion phosphors (UCPs) that are free from interference from biological sample autofluorescence have attracted attention for in vivo and in vitro bioapplications. However, UCPs need to be water-dispersible, nanosized, and highly luminous to realize broad applications. Therefore, the aim of this research is to develop UCPs that meet these comprehensive criteria for in vitro diagnosis. To combine nano size with high luminous intensity, β-NaYF:Yb,Er upconversion nanocrystals (UCNPs) codoped with Li and K are prepared that display high upconversion intensities as well as small size. The strongest green and red emissions of the NaLiKYF:Yb,Er nanocrystals are increased by 7 and 10 times, respectively, compared with those of the undoped NaYF:Yb,Er nanocrystals. A mild sol-gel surface modification method is used to produce water-phase dispersions and allow covalent biomolecule conjugation. The bioactivated UCNPs are used as a bioreporter and integrated with a classical lateral flow assay to establish an assay to accomplish simultaneous dual-target detection of Yersinia pestis and Burkholderia pseudomallei. The assay achieves a sensitivity of 10 CFU/test without cross-interference between two targets. The research provides a way to produce UCNPs with comprehensive properties for use as excellent optical reporters in in vivo and in vitro bioapplications.