Sensor Hears Cancer's Call
Tiny Biosensors Detect ‘Song’ of Cancer Markers, Say Researchers
Sept. 18, 2007 - Students at the Georgia Institute of Technology have invented a pinpoint-size sensor that hears the song sung by cancer-linked molecules dancing in a drop of blood serum.
They call the device the ACuRay chip. It's an array of electrodes deposited on a thin film. The array hums at a specific pitch when an electric current is applied. This technology is not new. A quartz watch works on the same principle.
What is new is the brainstorm of graduate students Anthony Dickherber and Christopher Corso. Working with research advisor William D. Hunt, PhD, the students stuck man-made antibodies on the device's tiny electrodes.
Antibodies are protein-based molecules designed to grab hold of another specific molecule -- and only that molecule. In their experiments, Dickherber and Corso used an antibody created by Ira Pastan, MD, at the National Cancer Institute. This antibody grabs a molecule called mesothelin, which is a marker for malignancies such as mesothelioma (asbestos-linked cancer), ovarian cancer, and pancreatic cancer.
When these cancer markers stick to the antibodies, they weigh down the electrodes beneath them. This changes the pitch at which the array hums -- so the device "hears" the presence of cancer markers.
"We have come up with something we think is potentially more sensitive than anything else out there," Dickherber tells WebMD. "We are not there yet. We proved the theory works, but we still have a lot of work to do to make this a practical device."
Corso, who plans to get an MD degree from Emory University after earning his PhD from Georgia Tech, says the device would have many applications beyond cancer screening.
"The device has the capability to detect other molecules indicative of other diseases," Corso tells WebMD. "It can also monitor the efficacy of certain treatments, or be used as an inexpensive home test for cancer patients to use to see if their cancer is returning after treatment."
Because the device is able to detect a very slight signal in a very busy environment, it has nonmedical applications as well. For example, Dickherber suggests it could be used to detect bioweapons, bombs, or trace amounts of illegal drugs.
Dickherber and Corso reported their findings in a poster presentation to this week's American Association for Cancer Research second international conference on Molecular Diagnostics in Cancer Therapeutic Development, held Sept. 17-20 in Atlanta.