Enhancement of biosensing performance using a polyaniline/multiwalled carbon nanotubes nanocomposite

In this study, an effective electrochemical method was successfully developed to produce polyaniline/multiwalled carbon nanotubes nanocomposite on interdigitated platinum microelectrodes for the enhancement of biosensing performance. Morphology and structure of nanocomposite were investigated by field emission scanning electron microscopy and ultraviolet-visible spectroscopy. Fourier transform infrared spectroscopy technique was used to identify the presence of polyaniline/multiwalled carbon nanotubes on the surface of microelectrodes. IgG polyclonal antibodies against Japanese encephalitis virus (JEV) were immobilized onto nanocomposite-modified microelectrodes, acting as an electrochemical immunosensor for label-free detection of JEV antigens. Results showed that the linear detection range of the immunosensor for JEV antigens was 2-250 ng/mL. The electrochemical impedance spectroscopy analysis also indicated that a negligible response was found when the immunosensor exposed to non-specific molecules. This work showed the potential use of polyaniline/multiwalled carbon nanotubes nanocomposite in the platform of electrochemical immunosensors for label-free detection of pathogens and small biomolecules.