doi:10.1038/nindia.2013.63 Published online 13 May 2013
Researchers have designed a new kind of sensor capable of detecting minute traces of Salmonella typhimurium, the bacterium that causes salmonellosis, a type of food poisoning. This sensor will be very useful during outbreaks of salmonellosis in humans.
Salmonella bacteria are generally transmitted to humans through the consumption of contaminated meat, poultry, eggs or milk triggering fever, abdominal pain, diarrhea, nausea and sometimes vomiting. There is currently no vaccine for preventing salmonellosis. Existing techniques for detecting this bacterium are not very sensitive and thus a better detection technique is needed.
The researchers fabricated a sensor using modified polyacrylonitrile fibers. On top of this sensor, they smeared an antibody against the Salmonella antigen using organic compounds. They then used this sensor to capture and detect S. typhimurium cells from various contaminated food samples.
The study found that the sensor could detect as few as ten S. thyphimurium cells in contaminated food samples. This sensitivity is far better than that commercial detection methods with immunomagnetic microbeads.
The sensor detected the targeted bacteria when investigated with food- and water-borne pathogens. It selectively detected the presence of S. typhimurium in milk samples even in the presence of Escherechia coli.