Researchers are using aerosol-jet-printing technology to create graphene biosensors that can detect histamine, an allergen and indicator of spoiled fish and meat.
The sensors were printed with high-resolution aerosol jet printers on a flexible polymer film and tuned to test for histamine.
The researchers dipped the printed sensors into tuna broth and watched the readings.
It turned out the sensors can detect histamine down to 3.41 parts per million.
The U.S. Food and Drug Administration has set histamine guidelines of 50 parts per million in fish, making the sensors more than sensitive enough to track food freshness and safety.
Making the sensor technology possible is graphene, a supermaterial that’s a carbon honeycomb just an atom thick and known for its strength, electrical conductivity, flexibility and biocompatibility. Making graphene practical on a disposable food-safety sensor is a low-cost, aerosol-jet-printing technology that’s precise enough to create the high-resolution electrodes necessary for electrochemical sensors to detect small molecules such as histamine.
The researchers have recently reported their sensor discovery in a paper published online by the journal 2D Materials.
The paper describes how graphene electrodes were aerosol jet printed on a flexible polymer and then converted to histamine sensors by chemically binding histamine antibodies to the graphene. The antibodies specifically bind histamine molecules.
The histamine blocks electron transfer and increases electrical resistance. That change in resistance can be measured and recorded by the sensor.
This histamine sensor is not only for fish. Bacteria in food produce histamine. So it can be a good indicator of the shelf life of food.
The researchers believe the concept will work to detect other kinds of molecules, too.
Beyond the histamine case study the aerosol jet printing and functionalization process can likely be generalized to a diverse range of sensing applications including environmental toxin detection, foodborne pathogen detection, wearable health monitoring, and health diagnostics.
For example, by switching the antibodies bonded to the printed sensors, they could detect salmonella bacteria, or cancers or animal diseases such as avian influenza.
News Source: Eurekalert
