Graphene oxide-based probe for detecting deltamethrin and emamectin benzoate pesticides in agricultural run-off†

Insecticides adversely affect aquatic ecosystems due to prolonged exposure, persistent nature, and bioaccumulation. Deltamethrin and emamectin benzoate are pesticides that can enter water resources via fruits and vegetables, causing severe concerns to living organisms. This study focuses on fabricating a probe for the selective solid-phase microextraction of targeted pesticides from agricultural runoff. The sorbent was designed using the novel dual-template graphene oxide-based molecularly imprinted organically modified silica. In this study, we investigated the effect of different parameters (time, pH, and temperature) on the efficacy of the sorbent using response surface methodology (central composite design). The sorbent exhibited high binding capacities of 42 mg g⁻¹ and 27 mg g⁻¹ for deltamethrin and emamectin benzoate, respectively. Percentage recoveries were 93.3% and 94.2% for deltamethrin and emamectin benzoate, respectively. The selective detection of deltamethrin and emamectin benzoate from agricultural runoff was confirmed by real-sample analysis using high-performance liquid chromatography.