Biosensor holds key to contamination

Research scientists at Clemson University, South Carolina, are developing a biosensor that will make contaminated food glow in the dark.

Research scientists at Clemson University are developing a biosensor that will make contaminated food glow in the dark.

A team of chemists, microbiologists and food scientists have devised a way to tether luminescent molecules to food pathogens, such as E.coli, and Salmonella. Using nanotechnology, the researchers are reportedly building a new screening method to protect America’s food supply.

‘What’s needed is a simple, low cost way to rapidly detect pathogens at the site of contamination, not having to wait for lab results,’ said food science professor and team leader Paul Dawson. ‘What we have worked on are particles that are luminescent, providing a way to flash an alarm to hold the food for closer examination.’

Chemists used a similar technique to identify worms in pecans. The worms would absorb a chemical that would glow under UV or ‘black’ light. Dawson, along with professors Ya-Ping Sun, Xiuping Jiang, Feng Chen and James C. Acton, have miniaturised the process by applying nanotechnology, the science of building structures at molecular and atomic levels.

Nature does a great job of putting together molecules and other nanoscale components in complex patterns, Dawson said. His team is working on a single molecule process, creating a ‘protein key’ that would ‘key and lock’ with another molecule and creating a bio-alarm, when key and lock fit.

Most pathogens and toxins have a unique ‘lock,’ and by attaching the matching ‘key’ on the surface of a luminescing nanoparticle, a nanosensor can be created. The sensor signal can be rapidly detected and be a first line of defence in identifying food or water that has been contaminated.

‘The nanoparticle can move into crevices in the food source, where a pathogen could be hidden from microscopic view,’ Dawson said. ‘The particle’s extremely small size increases the odds that the antibody and antigen will link, enabling the sensor to give off a glow. The more connections, the greater the glow.’

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