Detection of Newcastle disease virus using an evanescent wave immune-based biosensor

A fibre-optic-based evanescent wave biosensor has been used for the detection of virus. Polyclonal antibody directed against the model analyte, Newcastle disease virus, was covalently immobilized on aminosilane-coated quartz fibres, which served as the capture and concentration element of the sensor system. Radiolabelling studies demonstrated a high degree of antibody attachment to the quartz solid support. Maximal coverage could be attained with antibody solution as low as 10 mu g/mL and carbonyldiimidazole as the cross-linking agent. Fluorescein-labelled anti-NDV served as the detector antibody in a sandwich format. Assay times were approximately 15 min with a limit of detection of about 2 ng of purified virus in 0.2 mL sample volume. The biosensor detection system possesses several desirable characteristics such as a limited number of mechanical components, a multiple use active surface, and low baseline variation, which indicate that it has the potential to serve as an on-line continuous monitoring device of an automated or semi-automated detection system.