A novel aptasensing method for detecting bisphenol A using the catalytic effect of the Fe_3O_4/Au nanoparticles on the reduction reaction of the silver ions

摘要

The gold electrode was functionalized with anti-bisphenol A (BPA) aptamer and captured the BPA as analyte. By dropping the aptamer-modified magnetic Fe3O4/Au nanoparticles solution onto the electrode, a BPA molecule attaches to many aptamers that are in contact with a large number of Fe3O4/Au nanoparticles. The modified electrode were transferred to a solution containing Ag+ ions. Fe3O4/Au nanoparticles reduce the Ag+ ions to Ag0. A potential scan was applied for the oxidation of the Ag0-loaded magnetic nanoparticles to the AgCl. The magnitude of the stripping anodic signal of the Ag0 was related to the concentration of the BPA. The assay shows a detection limit of 0.6 fmol L-1 and linear range of 1 fmol L-1-150 pmol L-1 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.