The sensor being developed by Dr. Raj Mutharasan, a professor of chemical engineering at Drexel University, has a reported sensitivity of four bacterial cells per milliliter of solution:
The standard detection process of E. coli bacteria in food processing takes about 24 hours, and involves a trip to the laboratory. Mutharasan’s sensor empowers the food inspector. The sensor can be contained in a handheld device that is easy to use, quick with results and above all, accurate.
Results are ready in 10 minutes, and the prototype Mutharasan developed has a sensitivity of four cells per milliliter of solution.
The sensor uses E. coli antibodies to detect the bacteria in much the way that our bodies work. These antibodies are affixed to a narrow sliver of glass. Attached to the other end of the glass is a ceramic layer that generates voltage in response to applied mechanical stress.
A voltage is applied to the ceramic layer, making it expand and contract, causing the glass sliver to vibrate. The sensor detects changes in the glass sliver’s resonate frequency (the point where vibration is the greatest) and uses this to determine both the presence and concentration of E. coli bacteria.
The sensor can test both liquid and solid samples, as the same principles of resonate frequency apply. The sensor can be equipped with a wide range of antibodies to detect a multitude of pathogens, or it can be homozygous with a single antibody, enabling the sensor to detect even the minutest amounts of the harmful bacteria.