Graphene has a new utility. This conductor of electricity, formed by a sheet of carbon atoms joined one atom thick, is not only used to make headphones, ink, tires and many other uses already on the market, now it can also be a sensor that detects deterioration. of food.
Scientists from Iowa State University and Northwestern University in Illinois have introduced the sensor, created by the first aerosol jet-printed graphene electrodes on a flexible polymer substrate. The histamine antibodies were then chemically bound to the graphene.
Speaking clearly: histamines are also released in meat or fish in bad condition, and graphene is able to chemically bind to them, identifying their existence.
The idea is to build a device that is placed near a food, so that any histamine molecule that is present binds to graphene, blocking the transfer of electrons. This increases the electrical resistance of the material: the greater the number of molecules present, the greater the resistance, and the worse the food will be.
Therefore, by running an electric current between the electrodes, it is possible to measure the resistance and thus determine the histamine levels. In its current form, the sensor can detect histamines down to a concentration of 3.41 parts per million. For context, the US Food and Drug Administration defines spoilage in fish as just over 50 parts per million.
The sensor is cheap, and could easily be mass-produced. Additionally, by substituting other types of antibodies for histamine antibodies, the system could also be used to detect things like harmful bacteria or disease-associated biomarkers.
The technology is now being commercialized by the Iowa state spin-off company NanoSpy. It is described in an article that was published recently in the journal 2D Materials.
More information at news.iastate.edu.