Compared to other conducting polymers, polyaniline is unique and has received considerable attention due to its straightforward polymerization, environmental stability, unique conductive properties, and potential applications in electronic devices, batteries and sensors. However, native polyaniline is not electrochemically active and is a poor conductor in neutral solutions (required for most biosensor applications). It also limited both in the number of species that can be detected and in the selectivity of the detection. A major breakthrough was the discovery of self-doped polyaniline and the polyelectrolyte anion doped polyaniline, which brought polyaniline into biosensor field due to the improved redox activity and conductivity in neutral pH solutions. However, there are a number of tradeoffs, including reduced conductivity, chemical and mechanical stability due to steric effects.
In this presentation, we show that a self-doped polyaniline (poly (aniline boronic acid))/carbon nanotube composite is fabricated electrochemically by adding single-stranded DNA dispersed carbon nanotube into the polymerization solution. Cyclic voltammetry study of this composite demonstrates that not only the redox properties of polyaniline is reserved in neutral solutions (pH = 7.4) and the stability was greatly improved compared to poly (aniline boronic acid) itself. The morphology and the conductivity of the composite are studied by tapping mode atomic force microscopy (AFM) and conductive AFM. The interaction between the polymer and carbon nanotube is studied in a molecular structural level using Raman spectroscopy. Finally its applications in biosensor field will be presented.
Back to Inorganic and Organometallic Polymers IV
Back to The 37th Middle Atlantic Regional Meeting (May 22-25, 2005)