A recent deadly outbreak of hepatitis traced to imported green onions, which killed three people and sickened 600 in Pennsylvania, is one of the latest public health scares caused by food-borne pathogens.
Each year such outbreaks affect untold numbers of people and impose incalculable costs in terms of lost productivity and health care expenses. While nanomaterials are expected to alleviate some of these problems by helping keep products fresher longer, the more exciting application of nanotechnology is the development of nanosensors that can be placed in food production and food distribution facilities — and, longer term, in the packaging itself — to detect the presence of everything from E. coli and listeria to Campylobacter and salmonella.
Nanosensors can work through a variety of methods. One variation being developed by researchers at both Purdue and Clemson universities uses nanoparticles, which can either be tailor made to fluoresce different colours or, alternatively, be manufactured out of magnetic materials.
These nanoparticles can then selectively attach themselves to any number of food pathogens. Employees, using handheld sensors employing either infrared light or magnetic materials could then note the presence of even minuscule traces of harmful pathogens. The advantage of such a system is that literally hundreds and potentially thousands of nanoparticles can be placed on a single nanosensor to rapidly, accurately and affordably detect the presence of any number of different bacteria and pathogens.
A second advantage of nanosensors is that given their small size they can gain access into the tiny crevices where the pathogens often hide. Rashid Bashir, a researcher at Purdue and co-founder of BioVitesse, a biosensor company employing nanotechnology, hopes to reduce the time it takes to detect the presence of microbial pathogens from two to seven days down to a few hours and, ultimately, minutes or even seconds.