In an attempt to provide an insight into detection of specific viruses in biological samples, we report on quantitation of influenza A virus (IAV) in samples containing large amounts of extraneous bovine serum albumin (BSA), foetal bovine serum (FBS) and hepatitis B virus (HBV) vaccine. Detection was carried out using electrochemical impedance spectroscopy (EIS) with an antibody-neutravidin-thiol architecture immobilized on the surface of an Au electrode. A linear response of the EIS signal was observed for IAV concentrations ranging from 0 to almost 64 ng/mL. However, saturation of the EIS response was recorded for greater concentrations and only a 6% increase in signal occurred when the IAV concentration increased to 128 ng/mL. The limit of detection, determined at 8 ng/mL, remained relatively unaffected by the environment composed of 50 ng/mL of HBV and 12.5% of FBS. (C) 2011 Elsevier Ltd. All rights reserved.