Polyaniline Nanowires-Based Electrochemical Immunosensor for Label Free Detection of Japanese Encephalitis Virus

Polyaniline (PANI) conducting polymers have attracted increasing interest as a transducer material for biosensors applications. In this study, we demonstrate the use of PANI nanowires (NWs) as immobilization platforms in the configuration of an electrochemical immunosensor for label free detection of Japanese encephalitis virus. The PANI NWs were synthesized on the surface of an interdigitated platinum (Pt) microelectrode via electrochemical growth. The morphology and characteristics of the PANI NWs on the Pt microelectrode were verified by scanning electron microscopy and Fourier transform infrared spectroscopy. The anti- Japanese encephalitis virus polyclonal IgG antibody was then covalently immobilized on the PANI NWs-coated Pt microelectrode by using 1-ethyl-3-(3-dimethyaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimde (NHS). The detection of Japanese encephalitis virus antigens was analyzed by electrochemical impedance spectroscopy (EIS). The developed PANI NWs-based electrochemical immunosensor could detect the Japanese encephalitis virus with a detection limit below 10ng/ml. The results from EIS analysis also indicate that when the PANI NWs were exposed to nonspecific molecules, a negligible response was found, and it did not impact to the specificity of the sensor in the virus detection. This work shows the potential use of PANI NWs in electrochemical immunosensors for label free detection of other pathogens and small biomolecules.