Electrochemical synthesis of polypyrrole for biosensor application

Polypyrrole nanowires were electrochemically synthesised on platinum electrode at ambient temperature. The potentiostatic potential was set at 0.75 V in the presence of gelatin as soft mould. The whole process only took few hundred seconds. The morphologies, chemical composition and conductivity of nanowires were evaluated by means of Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and cyclic voltammetry (CV). The obtained nano-wire is around 50 nm in diameter with large surface, good conductivity. By surface enhanced Raman spectroscopy, the amine groups of polypyrrole were thought to be orientated upwards into the analyte which may facilitate the direct binding with DNA in DNA sensor.