A novel insight into fluorescent sensor for patulin detection using thiol-terminated liposomes with encapsulated coumarin-6 as signal probe

Nanocomposites of thiol-terminated liposomes encapsulating with coumarin-6 ( [email protected] ) were successfully prepared via a simple thin-film dispersion method to construct a novel fluorescent sensor for selectively detecting trace amounts of patulin. Thiol group ( SH) was designed not only as a specific recognition element to capture patulin, but also as a convenient linker for the further separation of patulin-derivatized and un-derivatized [email protected] by combination with magnetic NH 2 [email protected] 3 O 4 nanoparticles. Liposomes primarily provided an effective platform with a large surface area for facilitated accommodation of large amounts of recognition element ( SH group) and fluorophore (coumarin-6). In such an assay protocol, a reliable link was established between the changes in fluorescent intensity (ΔF) from the nanocomposites of [email protected] /NH 2 [email protected] 3 O 4 and the concentrations of patulin in the range of 0.05–20 ng mL −1 , with the correlation coefficient of 0.996. This approach also effectively eliminated the background interference from other mycotoxins and metal ions. Under the optimal conditions, the designed sensor displayed excellent performance for patulin analysis, with an extremely low detection limit (0.033 ng mL −1 ), high recovery (96.2–107.6 %) and excellent selectivity. Furthermore, the feasibility of its applications has also been demonstrated in the analysis of real juice samples, providing a novel tactics for rational design of a fluorescence assay, for point-of-care diagnostics of patulin, with great potential to be extended to other hazardous compounds by substitution of the recognition elements.