March 20, 2008

US scientists introduce nanotechnology biosensor to detect salmonella

A group of US scientists has found a way to detect foodborne pathogenic bacteria like salmonella through nanotechnology-based biosensor which promises bacteria detection with high sensitivity and high resolution.

The USDA collaborated with scientists from the University of Georgia and the Korea Food Research Institute to develop a novel and effective food-borne bacteria detection method.

Poultry meat and eggs are the common sources of foodborne pathogens, like salmonella. Early detection of these bacteria is critical to prevent disease outbreaks.

Previously, several methods have been developed to detect this pathogen, yet the biggest challenge remains in the speed and sensitivity of detection.

With this recent US study on a nanotechnology-based biosensor, the bacteria could be detected with high accuracy, the scientists said.

Yiping Zhao, an associate professor of physics at the University of Georgia, said the nanotechnology based biosensor has shown great potentials for protein, virus, and bacteria detection with high sensitivity and high resolution.

Zhao added that the bio-functional hetero-nanorod detection method has great potential in the food safety industry as well as in biomedical diagnostics.

The research team fabricated a hetero-structured silicon/gold nanorod array by the glancing angle deposition (or GLAD) thin film method and functionalised it with anti-salmonella antibodies and organic dye molecules.

Due to the high aspect ratio nature of the silicon nanorods, dye molecules attached to the silicon nanorods produce an enhanced fluorescence upon capture and detection of Salmonella.

With the growing role of nanotechnology in efficiently detecting foodborne pathogens, Zhao pointed some of these nanotechnology-enabled techniques, including detections by luminescence using quantum dots, localized surface plasmon resonance of metallic nanoparticles, enhanced fluorescence, dye immobilized nanoparticles, or Raman reporter molecule immobilized metallic nanoparticles.