A new electro-chemical biosensor has been developed which can detect minute amounts of antibiotics and the herbicide atrazine in food. Atrazine, and other similar herbicides is regulated because it causes contamination of ground and drinking water. Antibiotics, on the other hand, are often used to treat bacterial infections in farm animals, and are sometimes found in unacceptably high levels in food. these substances pose health hazards to the consumers.

[snip]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.

The sensor developed by scientists at the UAB and the CSIC will allow the detection of doses of atrazine at levels of 0.006 micrograms per litre, much lower than the maximum concentrations allowed by European regulations (0.1 micrograms per litre), and this can be done more quickly and cheaply than is the case of the chromatographs which are used today in food safety laboratories. As regards the detection of antibiotics, the sensor has a sensitivity of 1 microgram per litre for whole milk, while the legislation allows a maximum of 100 micrograms per litre.

The sensor is portable, and thus convenient for in situ testing.

Source and Photo: Universitat Autònoma de Barcelona