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Bongkrekic acid (BA) and isobongkrekic acid (iBA) are lethal bacterial toxins found in fermented foods, which have been associated with severe food poisoning incidents and high mortality. The rapid and accurate point-of-care detection of BA in real samples is indispensable for effective prevention. Current detection sensors for BA often suffer from insufficient stability, underscoring the need for innovative biosensing strategies. In this work, a dual-readout lateral flow biosensor was novelly presented, integrating strong fluorescence of Mn 2+ -doped Zn 2 GeO 4 persistent luminescence nanorods (ZnGeO:Mn PL NRs) and high chromaticity Fe 3+ -doped polydopamine nanospheres (Fe@PDA NSs). The biosensor provided both colorimetric and fluorescent signals based on fluorescence quenching via the inner filter effect (IFE). A monoclonal antibody (mAb) was employed as a specific recognition module for the simultaneous detection of BA and iBA. The mAbs exhibited remarkable specificity and sensitivity in ic ELISA, with half maximal inhibitory concentration (IC 50 ) values of 4.93 ng mL –1 for BA and 5.37 ng mL –1 for iBA. The developed PL-based fluorescence quenching lateral flow assay (LFA) yielded a visual detection limit (vLOD) of 0.5 ng mL –1 and a quantitative LOD of 0.16 ng mL –1 for BA detection. Moreover, the application in spiked rice and flour products exhibited recovery ratios ranging from 82.2 to 104.4%, confirming its reliability in complex matrices. Further validation with a panel of 20 real samples demonstrated high consistency with LC-MS/MS results, underscoring the practicality of the proposed PL-based LFA for the rapid screening of BA contaminants in food safety applications.
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