A novel sustainable biomass-based fluorescent probe for sensitive detection of salicylic acid in rice.

[Display omitted] • A ratiometric probe with higher stability was prepared with natural substances. • Fluorescence inner filter effect was triggered between SCQDs and Cur in Fe-MOFs. • Fe2+ from MOFs was ably used to capture active sites of Cur to avoid interference. • The developed probe shows high sensitivity to SA with LOD as low as 0.14 μmol/L. Herein, a ratiometric fluorescent probe was developed for sensitive detection of salicylic acid (SA) in rice using silk-derived carbon quantum dots @ Curcumin @ iron-based metal organic framework (SCQDs@Cur@Fe-MOFs). Fe-MOFs with porous structure not only provided holes for SCQDs to evade self-aggregation of SCQDs, but Fe2+ ions from MOFs was ingeniously employed to capture active sites of Cur, solving the problem of lacking sufficient specificity of Cur to SA while converting weak response signal to amplified "turn on" mode. Upon exposed to SA, the probe interacted with SA to form Cur-Fe2+-SA ternary complex, which inhibited the internal filtration effect between Cur and SCQDs, and triggered a cascade of response signaling. With this strategy, the proposed probe achieved sensitive determination of salicylic acid in rice with detection limit as low as 0.14 μmol/L. This study provides unique insight into constructing economical and eco-friendly fluorescent sensor for SA detection with superior performance. [ABSTRACT FROM AUTHOR]