DYNAMIC A.C.IMPEDANCE STUDY ON BIOFUNCTIONALISED GOLD NANOPARTICLE-POLYMER NANOCOMPOSITE ELECTRODE

Abstract

A polypyyrole and gold nanoparticle composite film has been prepared for the quantitative estimation of any enzyme or antibody in aqueous solution. The gold nanoparticles were synthesized using sodium citrate as the reducing agent. The nanoparticles were capped with 3- mercaptopropionic acid. The protein BSA, was covalently linked to the carboxyl group (COOH) of 3-mercaptopropionic acid (MPA) capped gold nanoparticles, embedded in the surface of the polypyrrole film electrochemically deposited onto an ITO coated glass plate. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were used for the characterization of different surfaces formed over the ITO coated glass electrode. GNPs provide a large surface area for immobilization of protein BSA and at the same time it provides high electrocatalytic activity to transfer electrons between BSA and electrode.The incorporation of gold nanoparticles into the polypyrrole film makes it more stable and conducting than simple polypyrrole film. This BSA/GNP(MPA)-PPy/ITO bioelectrode so prepared can be further use for biosensor application by immobilizing different antibody or enzyme.