Electrochemical synthesis of polyaniline nanocomposite based on modified gold nanoparticles and its application for electrochemical aptasensor

Abstract

The method of synthesis of polyaniline, as an important conductive polymer, and the conjugated metal nanomaterials applied in the polymer, determines the physicochemical properties of the final composites. In this study, we developed one-step electrochemical synthesis of new polyaniline, via applying modified gold nanoparticles (MAuNPs) as a weak acid. To this end, the Au nanoparticles were modified with 11-mercaptoundecanoic acid, and then they were directly applied as counter anions for the synthesis of a composite polyaniline. The steps of synthesis and the nanocomposites were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. This composite polyaniline was applied as an electrochemical aptasensor for the sensitive determination of lysozyme in human serum and urine. The aptasensor showed linearity range between 0.2 ng mL-1 n 2.0 ng mL-1 with detection limit of 120 pg mL-1.