Organic solvent-free solid-phase extraction of acetamiprid in food samples using Strep-Tag system integrated apta-magnetic sorbents

A novel magnetic sorbent, named ABA-(Strep-tag II)-STMB, was prepared by modifying the acetamiprid-binding aptamer (ABA) onto Strep-Tactin-coated magnetic beads (STMBs) via Strep-tag II. The integration of the Strep-tag system allows the elution of the target by the addition of D-biotin, which can compete with Strep-tag II for the Strep-Tactin sites on the magnetic beads, instead of organic solvents. The sorbent showed good selectivity and reusability, and the extraction efficiency could still reach 90.5 % after 8 reuses. Under the optimized conditions, the developed magnetic solid-phase extraction (MSPE) method exhibited good linearity in the range of 0.1-100 μM, with the limits of detection (LOD) of 0.017-0.019 μM, and the limits of quantification (LOQ) of 0.057-0.066 μM. The relative standard deviations (RSDs) were below 5.51 %. The spiked recoveries were 84.4 %-96.0 %. The analysis results were in good agreement with those of the QuEChERS method.