A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. Biosensors are used in medicine, bio-defense, food safety and other application areas. The use of nanomaterials has the potential to revolutionize the technology by allowing for smaller, faster and lower cost devices. Analysis can be done on-site rather than in the lab. Biosensors also include Bio-MEMS and NEMS devices. The nanoscale also allows the possibility of monitoring in vivo biological processes within single living cells, which is extremely valuable in cell biology. This newsletter looks at recent developments in biosensors that leverage nanotechnology.