PORTLAND, Ore.—An electronic nose may soon be able to detect cancer using a nanosensor array designed at the Israel Institute of Technology, according to researchers. The breathalyzer-like device used gold nanoparticles arrayed on a silicon substrate to identify not only the presence of cancer, but the specific kind detected.
The nanosensor array was fabricated from inter-digitated gold electrodes which were arranged in a circular pattern and deposited by an electron-beam onto silicon wafers capped with a thermal oxide. The millimeter-sized device separated its electrodes by just by 20 microns—each coated with nanoparticles created with "guest" receptors designed to attract a different type of cancer-marker molecule in breath. The assembly was them mounted on a printed circuit board inside the breathalyzer-like device. When exposed to breath from patients, any molecules occupying the guest receptors on the nanoparticles changed the electric conductivity of the electrode, thus identifying the type of cancer detected.
Researcher Hossam Haick led the Technion team in designing gold-nanoparticle sensors whose electrical conductivity changes when exposed to cancer markers in a patient's breath.
In tests with five different test groups of 177 volunteers, the nanosensor array was able to distinguish the breath of healthy individuals from those with lung, breast, colorectal and prostate cancer. Sensitivity required only a few molecules per billion to detect the cancerous states.
Next, the researchers say they want to develop a clinical version that can be used during routine annual medical examinations and which can not only can detect active cancers, but can also provide early warnings by detecting precancerous states too.