Multilayered Polypyrrole-Coated Carbon Nanotubes To Improve Functional Stability and Electrical Properties of Neural Electrodes

The surface of neural electrodes was modified with multilayered, polypyrrole (PPy)-coated, multiwalled carbon nanotubes (MWCNTs) via the layer-by-layer fabrication method. The modified electrode with PPy-coated MWCNTs exhibited a significant improvement over conventional Au electrodes and PPy-coated electrodes with respect to the electrical properties based on charge storage capacity (660 times larger), impedance (5 times lower), and electrochemical stability (3 times more stable). Positive results from the biocompatibility tests conducted on PC12 cells and RAW 264.7 further suggested that our multilayered, PPy-coated MWCNT was an excellent candidate for the surface modification of neural electrodes.