Arriving at a rapid and accurate diagnosis is critical during flu outbreaks. A new detection method developed by Ralph Tripp and co-workers, University of Georgia, USA, offers both a fast and accurate diagnosis.

The team has used gold nanoparticles (NPs) coated with antibodies that bind to specific strains of the flu virus. These NP–antibody complexes aggregate when the target virus is present in a sample. By measuring how the aggregated particles scatter laser light, the extent of aggregation and the mean hydrodynamic diameter can be determined. This is correlated to the virus concentration.

The technique can detect influenza at point-of-care within minutes at a very low cost and with a detection limit 1–2 orders of magnitude improved over commercial diagnostic kits. This should allow physicians to begin treatment early, when antiviral drugs, such as Tamiflu, are most effective.

• One-step assay for detecting influenza virus using dynamic light scattering and gold nanoparticles
  J. D. Driskell, C. A. Jones, S. M. Tompkins, R. A. Tripp,
  Analyst 2011, 136, 3083–3090.
  DOI: 10.1039/C1AN15303J