Layer-by-layer Assembled Graphene/Polyaniline Nanocomposite Film and Applied in Electrochemical Sensing

A novel graphene-polyaniline nanocomposite thin film was prepared by means of electrostatic layerby-layer (LBL) assembly of positive charged graphene sheets modified by poly (acrylic acid) (PAA-Gr) and negatively charged polyaniline (PANI). The use of PAA not only enhanced the dispersibility of the graphene sheets, but also provided a positive charge to the graphene thus facilitating the growth of multilayered films. Ultraviolet-visible spectrophotometry was used in the present work to monitor the LBL assembly process of {PAA-Gr/PANI}(n), multilayered films. Fourier transform infrared spectroscopy, X-ray diffraction patterns, scanning electron microscopy and cyclic voltammetry results demonstrated the successful fabrication of {PAA-Gr/PANI} hybrid multilayered films. Application of the {PAA-Gr/PANI}. hybrid film in electrochemical sensing was further demonstrated using H2O2 as a model analyte. The {PAA-Gr/PANI}(n) hybrid film was shown to have excellent electrocatalytic activity towards H2O2. The proposed {PAA-Gr/PANI}(n) film based sensor exhibited a wide linear detection range for H2O2 from 0. 005 mmol/L to 0. 3 mmol/L with a low detection limit of 1x10(-6) mol/L.