Multilayer membranes via layer-by-layer deposition of ascorbate oxidase and Au nanoparticles on the Pt electrode for reduction of oxidation current derived from ascorbate

A glass plate was alternately immersed in an Au colloid (10 nm φ) and an ascorbate oxidase (AO_x) solution (0.1 mg/mL, pH 6.8). Absorbance at 530 nm originating from the Au particles increased with the increasing number of depositions. The AO_x activity of the plate also increased as the plate was immersed in the AO_x solution. These results suggested that a multilayer membrane via the layer-by-layer deposition of AO_x and Au nanoparticles was formed on the glass plate. AO_x was also deposited on a Pt disk electrode using the same process. Using the (AO_x/Au)₁₀ modified electrode, the oxidation current of ascorbic acid (0.1 mM) decreased to 19% versus the unmodified electrode.