An innovative triple-channel probing strategy for ultrasensitive detection of quercetin in food matrices based on carbon dots

This work pioneered a triple-channel probing strategy for ultra-sensitively detecting of quercetin (QRT) using triple-emissive CDs ( TE -CDs) as a fluorescence reporter. The TE- CDs featured triple emission at 350, 415, and 485 nm under 290 nm excitation. Specifically, the introduction of QRT induced differential quenching effects on each emission band, thereby fostering a novel triple-channel sensing approach for QRT detection. This reporter demonstrated a linear detection range of 0.0–60.0 μmol L −1 and an ultralow limit of detection (LOD) of 0.06 μmol L −1 . Notably, QRT triggered a bright-to-dark cyan color transition, facilitating the development of a smartphone-integrated platform and a disposable paper device with LODs of 0.49 and 0.72 μmol L −1 , respectively. The proposed sensing platforms were successfully applied for the detection of in diversified food samples with satisfactory results. This work underscored the significance of TE -CDs as a triple-channel visual reporter, marking a pivotal advancement in enabling on-site detection of QRT.