Rapid and In Situ Synthesis of Gold Nanoparticles in Redox Multilayer Film for Biosensor Applications

Abstract

AbstractFerrocene‐grafted poly(ethyleneimine)/poly(acrylic acid) (PEI‐Fc/PAA) multilayer films were constructed via layer‐by‐layer assembly. When the PEI‐Fc/PAA films were immersed in HAuCl4 solution, Fc and the AuIII were converted to Fc+ and Au0, respectively, via the redox reaction of Fc and HAuCl4, and the PEI‐Fc/PAA@Au nanoparticles (NPs) multilayer films were rapidly fabricated. SEM and TEM results showed Au NPs were distributed homogeneously throughout the thickness of the whole film. The electron transfer behavior of PEI‐Fc/PAA@Au NPs multilayer films was investigated by cyclic voltammetry and AC impedance. The results indicated that the Au NPs greatly improve the conductivity of multilayer films and thus enhance the electrochemical properties of films. The PEI‐Fc/PAA@Au NPs films were further used for the fabrication of a hydrogen peroxide (H2O2) sensor, which showed good catalytic ability for the reduction of H2O2. This approach is expected to expand the routes towards rapid fabrication of Au NPs into multilayer films.