The sensor relies on a film of gold nanoparticles, which conducts electricity, layered over a carbon-based substrate. When a patient breathes into the device, particulates in the breath accumulate on the carbon layer and the sensor swells pushing the gold nanoparticles further apart, which, in turn, alters the resistance of the film. Each type of particulate has a unique effect on the resistance which can be measured by having a current flow through the sensor. “The user gets a figure on the device’s display panel that indicates whether the person is healthy or has cancer” [Physics World], says lead researcher Hossam Haick.
The new device can detect smaller amounts of the target chemicals and therefore diagnose lung cancer earlier, when treatments can be more successful. Link