An ultrasensitive ratiometric aptasensor based on the dual-potential electrochemiluminescence of Ru(bpy)3+in a novel ternary system for detection of Patulin in fruit products

To sensitively monitor trace-level of toxic patulin (PAT), an ultrasensitive PAT ratiometric aptasensor based on the dual-potential electrochemiluminescence (ECL) of Ru(bpy)32+ was first proposed. Noteworthily, Ru(bpy)3+- doped trimetallic nanocube (Ru@Tri) innovatively integrated the luminophore and cathode coreaction accel-erator (CCA), which could generate strong cathodic ECL in the existence of low concentration of K2S2O8. Simultaneously, anthocyanin-derived carbon quantum dots (anth-CQDs) prepared from purple potato skins was first served as a green anodic coreactant. And SiO2-coated anth-CQDs (anth-CQDs@SiO2) exhibited excellent performance for enhancing anodic ECL of Ru@Tri. Based on this, a novel ternary ECL system was established. In the presence of PAT, the ECL intensity ratio of anode to cathode (IECL-A/IECL-C) was significantly increased, and a low detection limit of 0.05 pg mL-1 was obtained. Moreover, when proposed method and high performance liquid chromatography (HPLC) were simultaneously applied to series of fruit products, the obtained results were completely consistent, reflecting its practicability.

Automated summary

An ultrasensitive PAT ratiometric aptasensor based on the dual-potential electrochemiluminescence of Ru(bpy)32+ was proposed for sensitive monitoring of trace-level PAT. The aptasensor integrated Ru@Tri nanocube as the cathodic coreaction accelerator and anth-CQDs@SiO2 as the anodic coreactant, allowing for the establishment of a novel ternary ECL system. The proposed method showed a low detection limit of 0.05 pg mL-1 and demonstrated practical applicability by comparing the results with HPLC analysis of fruit products.