Researchers from Iowa State University created an inexpensive graphene-based food sensor that can detect food spoilage.
The new sensors are printed on a flexible polymer film using high-resolution aerosol jet printers. The team's sensors were tuned to test for histamine. Histamine is an allergen and an indicator of spoiled fish and meat. The sensor can detect histamine down to 3.41 parts per million, which means it is sensitive enough to track food freshness and safety.
Graphene is a key element of the sensor. Aerosol jet printing technology was used to print graphene electrodes onto a flexible polymer. The printer had to be precise to create the high resolution electrodes and electrochemical sensors that detect small molecules. The sensors were converted to histamine sensors by chemically binding histamine antibodies to the graphene. Antibodies specifically bind to the histamine molecules in a sample. Histamine blocks electron transfer and increases the sensor’s electrical resistance. This change in resistance measured and recorded by the sensor.
This concept would work to detect other kinds of molecules. The functionalization process can be generalized for a diverse range of sensing applications. Switching antibodies bonded to the printed sensors could detect salmonella, cancers and animal diseases.
The sensor is cheap and can be scaled up for mass production.
A paper on the sensor was published in 2D Materials.