A biosensor developed by researchers at the National Nanotechnology Laboratory in Campinas, Brazil, has been proven capable of detecting molecules associated with neurodegenerative diseases and some types of cancer. The device is a single-layer organic nanometer-scale transistor on a glass slide. It contains the reduced form of the peptide glutathione, which reacts in a specific way when it comes into contact with the enzyme glutathione S-transferase, linked to Parkinson's, Alzheimer's and breast cancer, among other diseases.