Abstract:Based on Au@PDA core-shell nanoparticles (NPs) and the fluorescence quenching toward quantum dots, a dual-signal readout mode lateral flow immunoassay strip (LFIA) was fabricated for qualitative or quantitative determination of tebuconazole in fruits and vegetables. The effects of the preparation of Au@PDA and Au@PDA-antibody complex, the load of sensing elements and buffers of the strip were investigated on the strip sensitivity. Under the optimal conditions, the qualitative detection limit of tebuconazole by the naked eyes was 1 μg/mL in colorimetric mode and 100 ng/mL in fluorescent detection mode. The developed strip was applied in the tebuconazole detection in cucumber samples. And the results showed the interference of sample matrix could be eliminated by an appropriate dilution of cucumber sample extract. The limit of detection for tebuconazole in cucumber was 0.8 mg/kg, meeting the limit requirement of national safety standard.