Aqueous dispersions of SWCNTs using pyrrolic surfactants for the electro-generation of homogeneous nanotube composites. Application to the design of an amperometric biosensor

Abstract : A new approach for the fabrication of homogeneous single-walled carbon nanotube/polypyrrole composites is presented. Stable SWCNT dispersions were obtained using the electropolymerizable (11-pyrrolyl-1-ylundecyl)triethylammonium tetrafluoroborate as surfactant. For these dispersions, we used commercially available HiPco® SWCNTs (purified) as received without any further treatment. Highly homogeneous composite materials could be electrogenerated, which were analyzed by scanning electron microscopy showing thin SWCNT bundles embedded in the polymer matrix. The quality of the SWCNT composite was tested with regard to its performance for biosensor applications. Enzymes like glucose oxidase and tyrosinase were entrapped in this copolymer during electropolymerization. The resulting glucose and catechol biosensors exhibit a drastic increase of sensitivities and maximum currents compared with the same sensor setup without nanotubes.