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.