Researchers have devised a sensor that can detect a food-poisoning bug Salmonella typhimurium, which contaminates food and causes salmonellosis when ingested. The hand-held sensor sniffs out the bug very fast in contaminated food samples1.

Available techniques to detect salmonellosis are expensive and take more than two days. To invent a faster and cheaper method, the researchers designed a simple sensor using oxidized macroporous silicon and trapping the antibody generated in response to Salmonella infection.

The sensor was exposed to a solution containing S. typhimurium in the presence of current. It detected the bug with the antibody-antigen binding method within 30 minutes. It can be used for five consecutive days after thorough washing in a well-equipped lab. This is very advantageous for field deployable sensors.

"Our aim is to develop a hand held biosensor kit to detect and quantify (to some extent) bacterial strains (like Salmonella and E. coli) present in human blood and urine," says Chirasree Roy Chaudhuri, one of the researchers. This method can also be applied for bacteria detection in food products like milk, butter and others, she says.

The authors of this work are from : Department of Electronics and Telecommunication Engineering, Bengal Engineering and Science University Shibpur, Indian Association for Cultivation of Science, Department of Neurobiology, Indian Institute of Chemical Biology, Department of Electronics and Telecommunication Engineering, Jadavpur University, West Bengal, India.