Dual-Mechanism\nQuenching Electrochemiluminescence\nSystem by Coupling Energy Transfer with Electron Transfer for Sensitive\nCompetitive Aptamer-Based Detection of Furanyl Fentanyl in Food

Resonance energy transfer (RET) quenching is significantly\nimportant\nfor developing electrochemiluminescence (ECL) sensors, but RET platforms\nface challenges like interference from other fluorescent substances\nand reliance on energy transfer efficiency. This study used Zn-PTC,\nformed by zinc ions coordinated with perylene-3,4,9,10-tetracarboxylate,\nas a dual-mechanism quencher to reduce the ECL intensity of carbon\nnitride nanosheets (Tg-CNNSs). Co<sub>3</sub>O<sub>4</sub>/NiCo<sub>2</sub>O<sub>4</sub> acts as a coreaction promoter, enhancing and\nstabilizing the luminescence of Tg-CNNSs. Zn-PTC absorbs energy from\nTg-CNNSs, altering the fluorescence lifetime to confirm energy transfer,\nwhile energy-level matching demonstrates electron transfer. By leveraging\nboth RET and electron transfer mechanisms, the designed ECL aptasensor\nsignificantly reduces signal fluctuations that may arise from a single\nmechanism, resulting in more stable and reliable detection outcomes.\nThe ECL aptasensor designed for furanyl fentanyl (FUF) detection shows\nexcellent performance with a detection limit of 5.7 × 10<sup>–15</sup> g/L, offering new pathways for detecting FUF and\nother small molecules.