Impedance sensing platform for 4,4′-dibromobiphenyl based on a molecularly imprinted polymerized ionic liquid film/gold nanoparticle-modified glassy carbon electrode

1-Vinyl-3-butyl-imidazolium hexafluorophosphate (VBimPF₆) was used as a functional monomer to fabricate an imprinted film onto a glassy carbon electrode modified with gold nanoparticle under the conditions applying 4,4′-dibromobiphenyl (DiBB) as a template, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, and ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine as initiators at room temperature. After the fabrication process, the embedded DiBB template was removed to obtain a new electrochemical sensor with high specific recognition sites toward DiBB. The morphology of the electrode surface was characterized with scanning electron microscope and atomic force microscope. Electrochemical impedance spectroscopy was used to test the sensing performances of this newly developed electrode. The imprinted film exhibited high selectivity and sensitivity in the determination of DiBB. Under optimized conditions, the charge transfer resistance attributed to the interaction of DiBB with the electrode was found linearly related to the logarithm of DiBB concentration in the range from 0.005 to 10.0 μM. The estimated detection limit is 0.001 μM (S/N = 3). Therefore, this electrode shows great application potential for the determination of trace DiBB contents in soil samples.