A team of MIT researchers have developed nanoparticle sensors that could eventually be used to monitor tumors or other diseases, as well as act as a tool to diagnose illnesses. These nanoparticles are made of polymer chains that can bind to the sensors a doctor needs. For instance, in the scientists' tests, they used an MRI contrast agent called nitroxide along with Cy5.5, which glows when it encounters vitamin C, as sensors. These individual strands then merge to form the structure you see above, which the researchers call "branched bottlebrush polymer." As you can guess, the bottlebrush polymer the team developed for the study can perform MRI and detect vitamin C, as detailed in their paper recently published in Nature. Since nitroxide grabs electrons from the vitamin and remains inactive in its presence, the scientists don't get confused by the two different signals.