A silicon nanowire sensor has the potential to detect diseases never before possible with conventional tests, according to researcher Charles M. Lieber, a professor of chemistry at Harvard.

An array of sensors could ultimately be configured to a handheld PDA-type device or small computer, allowing almost instant test results during a doctor’s visit or possibly even at home by a patient. It could potentially be used to screen for disease markers in any bodily fluid, including tears, urine and saliva, he says.

The sensor also shows promise for early detection of bioterrorism threats such as viruses.

To demonstrate the effectiveness of the sensor device, the researchers grafted nucleic acids to a silicon nanowire. The nucleic acids were specifically designed to recognize a particular mutation site in the cystic fibrosis gene that is responsible for most fatal cases of the genetic disease. The researchers then exposed the nanowire to fragments of the cystic fibrosis gene, some with the lethal mutation and some without it.

The researchers found that they could successfully distinguish between the two types of gene fragments, even down to extremely low levels that would have been missed by conventional DNA sensors.

Unlike conventional DNA detection methods that require a complex procedure called PCR amplification to view the results, the nanowire sensor does not need such sophisticated and expensive techniques, which could ultimately speed up genetic testing while reducing costs.

American Chemical Society press release