Size Matters: Biosensors behave oddly when very small

Physicists have built tiny instruments sensitive enough to detect single molecules of DNA, and the construction of these sensors generally follows a simple rule: the smaller the better. However, this rule might have a limit, a new study finds.

TINY CONCERN. Antibodies, depicted in green and blue, bunch up toward the free end of a nanosize cantilever instead of coating the sensor evenly.