Scientists at Spain's Universitat Autònoma de Barcelona have created a portable electro-chemical biosensor that detects and identifies traces of toxic chemicals such as pesticides and antibiotics in food including milk, produce, water and orange juice. The biosensor can detect even small amounts of atrazine, a commonly used herbicide in conventional agriculture in the United States, antibiotics used to promote the growth of animals raised for food and sulphanilamides used to treat sick animals in factory farming.The chemical mechanism to detect contaminants in a sample is very similar to that used by the immune system to identify a virus or bacteria in the body. The organism attacks an infection by generating antibodies which hook onto, for example, a specific type of virus. Hence the virus is identified and may be eliminated. In the case of the sensors, specific antibodies for atrazine have been used (in the case of pesticides) and for sulphanilamide (in the case of identifying antibiotics). Once the antibodies hook onto the contaminating particles they are attracted to the surface of a transductor which converts the contact with the antibodies into electrical signals. By measuring these electric signals the device can determine the concentration of contaminants in the sample.
According to Isabel Pividori, researcher at the UAB Sensors and Biosensors Group and co-director of the study, "due to their characteristics, such as their ability to carry out measurements in the field, the biosensors are analytical tools which have numerous applications in the agro food industry, and can be used as an alarm for the rapid detection of 'risk' of contamination in practices based on Risk and Critical Control Point Analysis".
