Highly sensitive detection of quercetin based on aggregation-induced electrochemiluminescence active polymer dots

Ensuring appropriate quercetin (Qn) levels in food is essential for food safety and human health. In this work, we developed a sensitive electrochemiluminescence (ECL) sensing platform for Qn analysis, utilizing aggregation-induced ECL (AIECL)-active polymer dots (Pdots) as the emitter. Benefiting from the restriction of intermolecular motions in the aggregated states, the prepared Pdots exhibit efficient ECL emission. Upon Qn introduction, the ECL signal was effectively quenched via a dual-path electron and/or energy transfer mechanism. This "signal on-off" strategy enables ultrasensitive and highly selective Qn detection, achieving a broad linear range from 0.1 nM to 1.0 mM with a low detection limit of 41 pM. The sensor was successfully applied to determine Qn in various real food samples with satisfactory recoveries. This work not only offers a reliable method for Qn monitoring but also highlights its promise for advancing food safety.