A novel aptasensing method for detecting bisphenol A using the catalytic effect of the FeO/Au nanoparticles on the reduction reaction of the silver ions.

The gold electrode was functionalized with anti-bisphenol A (BPA) aptamer and captured the BPA as analyte. By dropping the aptamer-modified magnetic FeO/Au nanoparticles solution onto the electrode, a BPA molecule attaches to many aptamers that are in contact with a large number of FeO/Au nanoparticles. The modified electrode were transferred to a solution containing Ag ions. FeO/Au nanoparticles reduce the Ag ions to Ag. A potential scan was applied for the oxidation of the Ag-loaded magnetic nanoparticles to the AgCl. The magnitude of the stripping anodic signal of the Ag was related to the concentration of the BPA. The assay shows a detection limit of 0.6 fmol L and linear range of 1 fmol L-150 pmol L and. The applicability of the aptasensor is measured by its successful use in the sensing BPA in water, milk and juice samples and measuring BPA migration from different commercial plastic products.