Electrochemical sensor for imidacloprid detection based on graphene oxide/gold nano/β-cyclodextrin multiple amplification strategy

The key to improving the sensitivity of electrochemical sensors for direct detection is the introduction of catalytically amplified nanomaterials. Accordingly, in this study, a new strategy for the preparation of electrochemical sensors with multiple amplification effects is proposed. Graphene oxide (GO), gold nanoparticles (Au NPs), and β-cyclodextrin (β-CD) were introduced to the surface of a glassy carbon electrode via cyclic voltammetry to prepare a modified electrode sensor with a GO/Au NPs/β-CD thin film. The prepared sensor effectively catalyzed and amplified the reduction current of imidacloprid in a B-R buffer with pH = 5.0 owning to the multiple amplification effects of GO/Au NPs/β-CD. A good linear relationship was observed the level of the reduction current response and the imidacloprid at concentrations ranging from approximately 5 × 10 −10 to 3000 × 10 −10 mol/L; thus, a new imidacloprid detection method using an electrochemical sensor was established. The new method, whose detection limit reached 1.33 × 10 −10 mol/L, was tested on actual samples, achieving recoveries of 92.0 % to 110.0 %.