Upconversion Fluorescence Nanoprobe-Based FRET for the Sensitive Determination of .

as a typical foodborne pathogen has strong survivability in the environment or food, leading to infectious diseases, yet its rapid detection technology with high selectivity and sensitivity remains challenging. In this study, complementary strand modified upconversion nanoparticles (UCNPs) can offer stable yellow-green fluorescence at 500-700 nm excited by a 980 nm laser. Importantly, aptamer modified gold nanoparticles (GNPs) formed by "Au-S" bond act as a fluorescence resonance energy transfer (FRET) donor and recognition element that can bind specifically to and significantly quench the fluorescence of complementary strand modified UCNPs. As a result, the fluorescence of our developed nanoprobe increased linearly with the increase in in a wide range from 1.2 × 10 to 1.2 × 10 CFU/mL and the detection limit was as low as 30 CFU/mL. Moreover, the fabricated upconversion fluorescence nanoprobe can achieve detection in contaminated chicken without enrichment in 1 h.