Researchers from the Georgia Institute of Technology conceived and developed the ACuRay chip, standing for ACoustic micro-arRay – a device that shares more in common with an inexpensive wristwatch than the sort of cutting edge molecule-sorting apparatuses currently used by researchers and clinical laboratory technicians. The array consists of a series of electrodes deposited on the surface of a thin film of zinc oxide, which allows the device to resonate, or vibrate, at a specific frequency when a current is applied, much like the quartz timing devices used in many clocks and watches.
“The sensor itself is built on a base of silicon, like a computer chip, and could be mass-produced using very well known and inexpensive microelectronic fabrication techniques,” Anthony Dickherber, a graduate student in the School of Electrical and Computer Engineering at Georgia Tech said.
To turn this array into a sensor, the researchers coated the zinc oxide surface with mesothelin-specific antibodies. These molecules are engineered versions of the antibodies the immune system creates to identify foreign intruders, such as microbial parasites. Mesothelin is a cell-surface protein that is highly expressed in mesothelioma, ovarian cancer, pancreatic cancer and other malignancies.
When the mesothelin binds to an antibody, the added mass changes the frequency at which the acoustic wave passes between the electrodes on the surface of the device. The device is able to “hear” the pitch change due to nanomolar concentrations of mesothelin (just a few molecules amid billions) binding to antibodies on the chip. The technology has the potential of detecting biomarkers in even lower concentrations than those tested, Dickherber said.
MEDICA.de; Source: American Association for Cancer Research