Scientists in Norwich have struck on an unusual way to test for flu - after discovering that gold can be used to detect the virus.

Researchers on the Norwich Research Park have patented a quick, simple dipstick flu test using sugar tagged with gold nanoparticles.

Professor Rob Field, from the John Innes Centre and Professor David Russell, from the University of East Anglia, discovered that a gold solution changes colour in the presence of the flu virus.

And the colour which it changes to is different, depending on the strain of flu.

Results published in Organic & Biomolecular Chemistry show that gold nanoparticles can be used to detect the human influenza virus X31 (H3N2) within half an hour and to distinguish between human and avian influenza.

Prof Field said 90pc of human infections use carbohydrate recognition to bind with targets in the body and by creating a solution of sugars tagged with gold particles, that can help spot the infections.

He said if the flu virus is present, it will attach to a sugar, pulling particles closer together.

Human and avian flu have a preference for different sugar chains, so the solution changes colour depending on which is present.

Prof Field said: 'The same basic principles can be applied wherever rapid detection is required from detecting superbugs in hospitals to biohazards such as ricin.'

Prof Russell said: 'Our technique based on gold nanoparticles is much faster than current methods of detection.'

Scientists say quick diagnosis of flu is important because vaccination and antiviral drugs need to be administered to patients within 48 hours of infection to prevent new pandemics arising.

Prof Field said: 'We are now looking for a diagnostics company to help us bring it to market.'

The researchers have already developed a carbohydrate-based sensor to detect cholera in contaminated water supplies.

Prof Russell leads a spinout company, Intelligent Fingerprinting, based on drug and drug metabolite screening using the sweat contained in fingerprints.

Government funding is being used to develop a patented handheld device for use in Accident and Emergency and coroner services.