Supersensitive electrochemiluminescent detection of permethrin based on 3D graphene hydrogel coupled with rough SiO ₂ @Ru(bpy) ₃ ²⁺ nanoparticles

Pesticide residues are toxic contaminants in agricultural products, threatening human health throughout the food chain. In this paper, an electrochemiluminescence (ECL) sensor based on rough Ru(bpy) 3 2+ -doped silica nanoparticles (rSiO 2 @Ru(bpy) 3 2+ NPs) was developed for the sensitive detection of permethrin (PET) residues in vegetables. The sensor was fabricated by modifying a glassy carbon electrode (GCE) with graphene hydrogel (GH). The ECL produced by the rSiO 2 @Ru(bpy) 3 2+ /tripropylamine (TPA) system exhibited a proportional quenching response to the concentration of PET, leading to a decrease in the ECL intensity. Under optimized conditions, the ECL intensity showed a linear relationship with the logarithm of PET concentration across a wide range from 1.0 × 10 −11 M to 1.0 × 10 −7 M, with a detection limit of 3.3 × 10 −12 M (S/N = 3). The proposed sensor demonstrated high sensitivity and was successfully applied to determine PET levels in real vegetable samples, offering a reliable approach for monitoring pesticide residues in agricultural products.