In Iowa, a team at Iowa State University’s Department of Mechanical Engineering created a flexible, low cost and disposable biosensor that can detect pesticides in soil. Made of graphene, a strong and stable nanoparticle, the biosensor provides instantaneous feedback; much better than the time and money involved in taking a sample, sending it to a testing lab and waiting on the results.
The biosensor is made by printing graphene ink onto paper. Then, a laser traces over the ink to improve its electrical conductivity by welding together flakes of the graphene ink; making a three dimensional nanostructured surface.
In the field, strips of the graphene-printed biosensor paper are dipped into a slurry of soil and water and then the strip is connected to an electrochemical reader to test for pesticides. Test results can help farmers quickly understand how much pesticide is needed to maintain healthy crops and minimize environmental damage.