Cancer is the number one health problem worldwide. Doctors all over the world think that if cancer could be detected early when they are just few thousand cells, it is easier to treat. Unlike certain diseases which develop unique antibodies, cancers are difficult to spot. Nonetheless, they do leave a fingerprint: a change in a number and type of proteins that regularly circulate in the blood.
Now doctors can determine which combination of proteins that makes up the unique signature of a particular cancer. Sometimes they need to measure 20-25 different proteins in order to diagnose one cancer in the early stage.
Scientist have developed nanosize sensor called nanowire that can electronically detect a few protein molecule along with other biochemical markers that are early sign of cancer. The strategy is to coat a collection of nanowires with different compounds, each of which binds to one particular marker. When the marker latch on, it change the conductivity of the nanowire, creating a tiny but measurable alteration in current. Doctors have combined ten of thousand of these sensors onto a single chip which allow them to detect cancer signifying molecule in the blood while their concentration is still low. The chip also allow doctors to identify what type of cancer are present.