Novel Single Gold Nanowire-based Electrochemical Immunosensor for Rapid Detection of Bovine Viral Diarrhoea Antibodies in Serum

Abstract

Bovine Viral Diarrheoa (BVD) is a worldwide disease with severe financial implications for the Bovine beef and dairy industries. A key challenge to BVD eradication is that the requirement to send samples to, and receive results from, specialized laboratories slows down the diagnostic process and leads to uncontrolled spread of the virus within a herd until diagnostic confirmation is received. Consequently, rapid identification of BVD is now critical for herd protection and prevention of costly herd outbreaks and new diagnostic devices, suitable for on-farm analysis, that deliver rapid and early identification of animal disease states, are required. We report, here, an electrochemical onchip fully integrated nanowire based immunosensor device for detection of BVD in serum. The capture biomolecule, BVD virus, is covalently immobilized via a carboxylic terminated polymer firstly electrodeposited onto a single nanowire. Electrochemical characterization including faradaic electrochemical impedance spectroscopy and cyclic voltammetry is performed. Label free immunologic detection of antibodies (10 μg/mL, 20 min) is first demonstrated using a bovine serum albumin as a model antigen-antibody system. Then, the immunosensor is applied to detection of bovine viral diarrhoea antibodies (10 μg/mL, 20 min) in both buffer and serum. The sensor clearly discriminates between positive and negative infected bovine sera. This study clearly shows the potential of this chip nanowirebased electrochemical sensor for immunoassays application in serum with a view to developing portable devices for on-farm diagnosis or therapeutic monitoring in animal health applications.