Ru@UiO-OH as a stable electrochemiluminescence emitter and FeMoO4-Au as a Co-reaction accelerator for ultrasensitive aptasensing of zearalenone

초록

To meet the demand for the detection of the mycotoxin zearalenone (ZEN) in cereals, this work developed an electrochemiluminescent (ECL) aptamer sensor with high sensitivity and selectivity. The sensor used a zirconium-based metal-organic framework (UiO-OH) to encapsulate the classical luminescent tris(2,2′-bipyridine)ruthenium(II) (Ru(bpy)32 + ) to form a Ru@UiO-OH composite material, which effectively solved the problem of unstable signal of Ru(bpy)32+ in water. Meanwhile, the introduction of divalent iron molybdate (FeMoO4) as a co-reaction promoter efficiently catalyzed the generation of a large number of sulfate radicals from the K2S2O8 through the synergistic effect of Fe/Mo binary metals, which significantly enhanced the ECL signal. The FeMoO4 surface-loaded gold nanoparticles (Au NPs) further accelerated the electron transport and provided sites for DNA immobilization. This sensor exhibits good linearity for ZEN in the detection range of 100 fg/mL to 1 μg/mL, with a detection limit as low as 4.35 fg/mL. The sensor demonstrated excellent stability, selectivity and sensitivity, providing a new strategy for the rapid and sensitive detection of ZEN in grains, which is of great significance for ensuring food safety.

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