Ultrasensitive Electrochemiluminescence Aptamer Sensor Based on Ru@ZIF-Pd Cathode for Acetamiprid Detection

Ru(bpy)₃²⁺ is commonly used in electrochemiluminescence (ECL) as a conventional luminophore. However, Ru(bpy)₃²⁺ can leak off the electrode surface, resulting in a reduced ECL signal. In this work, a nanocube composite material Ru@ZIF was prepared by incorporating doping luminescent Ru(bpy)₃²⁺ into the skeleton of Zn(II) ions and 2-methylimidazole (2-MI), and the ECL probe Ru@ZIF-Pd was prepared by in situ growth of Pd nanoparticles (Pd NPs). Potassium persulfate (K₂S₂O₈) was used as a coreactant to investigate the cathodic ECL behavior. The ZnCoCH@MXene-Au (ZC@T-Au) was used as a coreactant accelerator to promote the production of SO₄^•-, which effectively amplified the ECL intensity of Ru@ZIF-Pd. Under optimal experimental conditions, we successfully constructed an aptamer ECL sensor, which achieves an accurate detection of acetamiprid from 0.1 fM to 10 μM with a detection limit of 0.029 fM. It provides a potential idea for the detection of pesticide residues in food.