Detection of this food contaminant is critical to control food safety, and while different methods have been employed to detect Salmonella, the biggest challenges in the various approaches have been speed and sensitivity.
According to the US Department of Agriculture’s Research Service (ARS), collaboration between its engineers at the Quality and Safety Assessment Research unit and scientists at the University of Georgia has resulted in a nanorod-based biosensor that enables rapid detection of the Salmonella pathogen with high sensitivity.
Nanoscale sensors have been emerging as a feature of recent nanotechnology applications for food safety and quality measurement.
Lead researcher Bosoon Park explained that these new biosensors include fluorescent organic dye particles attached to Salmonella antibodies; the antibodies latch onto Salmonella bacteria and the dye lights up like a beacon, making the bacteria easier to see.
Salmonella is one of the most common enteric (intestinal) infections in the US with an estimated 1.4 million cases of salmonellosis occurring each year: 95 per cent of those cases are foodborne-related.
The ARS team of collaborators claims the sensor could be adapted to detect other foodborne pathogens as well.
There are examples of biosensors in nature, continued the researchers, such as insects that detect tiny amounts of sex pheromones in the environment and use them as a beacon to find mates and fish that use natural biosensors to detect barely perceptible vibrations in the surrounding water.
Nanotechnology, which uses tiny particles measuring one billionth of a metre, is already used for various applications in areas such as food supplements, functional food ingredients and in food packaging. In broad terms, nanotechnology refers to controlling matter at an atomic or molecular scale of between one and 100 nanometres (nm) - one millionth of a millimetre. At present, the main uses for foods are said to be in food packaging and barrier materials, with some applications in nutraceutical delivery. Other uses under investigation include processing - such as programming of foods to release flavour at a particular time, or nutrients in a certain part of the body where they can have an effect.
Estimates of the future market for nanotechnology range from €750bn to €2,000bn by 2015 according to the European Commission, with predictions for the number of new jobs created by the industry standing at around 10 million.
However, the technology has suffered from a lack of public understanding and consumer concerns over the safety of some of its applications.