Researchers from Harvard and MIT have designed a microfluidic device that uses porous "forests" of carbon nanotubes to detect individual cancer cells or viruses such as HIV in a blood sample.
Harvard's Mehmet Toner, MIT's Brian Wardle and colleagues improved upon a device developed four years ago that had forests of silicon posts to detect target cells.
By making the posts out of porous carbon nanotubes, which are cylinders of carbon atoms, and attaching various antibodies to them, sample fluid can flow through and around the "trees," increasing the chances of detection.
The antibodies will bond to targets chemically, but the device also works mechanically by trapping particles depending on the distance between the trees. The forest has 10 billion to 100 billion carbon nanotubes per square centimeter, and is 99 percent air.
It can collect cancer cells eight times better than the original device, according to an MIT release.
The device is about the size of a dime and the detection method is described in a study that appears online in the journal Small.
Normally, circulating tumor cells are very difficult to detect, and the device may be useful in discovering when cancer has metastasized to other parts of the body. The researchers are working to tailor the device to HIV detection.
Toner said the device could be developed into a cheap testing kit for use in developing countries where doctors don't have access to expensive lab equipment.
The original device, meanwhile, is being tried out in hospitals and may be commercialized in a few years.