Scientists in Denmark have designed a new sensor to detect cells that over-express folate receptors, including cancer cells. Jaime Castillo-León from the Technical University of Denmark and colleagues' sensor consists of an electrochemical platform composed of graphene and peptide nanotubes with folic acid.Cancer cells have a high requirement for folic acid as it is necessary for their metabolism, so the cells have 500 times more folate receptors compared with a healthy cell, explains Castillo-León. The receptors are like antennas on the surface of the cell membrane that seek out folic acid. The cancer cells interact with the electrochemical platform,...