A team of researchers from the US has developed a new rhodium-based microchip which could help detect a range of medical conditions through DNA matching, the New Scientist reported on Friday (16th January).

Christine Keating and her colleagues from Pennsylvania State University found that if bacteria are present, their DNA chains match up with a corresponding rhodium nanowire - thus changing its conductivity - meaning individual pathogens can be detected by assessing when this process occurs.

They made the discovery after using a conventional microchip which had small depressions called 'microwells' in the centre, each containing an electrode on either side.

The subsequent creation of an electric field gradient enables the wires - which measure 700 nanometres wide and eight micrometres long - to be controlled smoothly with a handheld device.

Ms Keating told the news provider: "Our DNA-coated rhodium nanowires 'feel' the electric field at a distance and are then drawn towards the region spanning our guide electrodes until they reach a microwell, which they then snap into due to the higher field strength there."

The tests conducted by the researchers proved to be a huge success, as the chip detected the presence of DNA from hepatitis B, hepatitis C and HIV.

Geoff Thornton, from the London Centre for Nanotechnology at University College London, added in an interview with New Scientist: "This work sounds exciting. We don't have a means of positioning a nanowire precisely where we want it right now."

The researchers are now focusing on producing a full prototype with the required transistors for ascertaining the conductivity of individual nanowires.

Source:

Nanotech gadget could diagnose any disease (16/01/09)
http://www.newscientist.com/article/dn16434-nanotech-gadget-could-diagnose-any-disease.html