Polypyrrole-derived carbon nanotubes for potential application in electrochemical detection of dopamine

Dopamine (DA), as a crucial signal molecule in neurological diseases, can be detected by electrochemical technology because of its redox property. A novel electrochemical sensor for dopamine (DA) is developed based on heteroatom-doped carbon nanotubes derived from polypyrrole. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, specific surface analyzer, and cyclic voltammetry are employed to characterize the microstructure and property of the products. The electrochemical catalytic activities of heteroatom-doped carbon nanotubes modified glassy carbon electrode (GCE) towards DA are further investigated by cyclic voltammetry, amperometry, and differential pulse voltammetry. The results indicate that heteroatom-doped carbon nanotubes prepared by pyrolysis of polypyrrole nanotubes at 800 °C possessed higher specific surface area and better electrochemical activity compared with others obtained at different temperatures. Therefore, the electrochemical sensor fabricated by the heteroatom-doped carbon nanotubes shows excellent detection ability towards DA as well as remarkable anti-interference ability and stability. These features collectively endow the polypyrrole-derived carbon nanotubes with a promising application for the fabrication of electrochemical sensors.