Living organisms interface with computers

An electronic switch based on DNA has been developed by researchers at the University of Portsmouth. And it has an immediate practical application in toxin detection and could be used in a biodefence role as a biological sensor to detect airborne pathogens.

The development is a world-first bio-nanotechnology breakthrough that provides the foundation for the interface between living organisms and computers.

The technology is called a 'nanoactuator' or a molecular dynamo. The device is about one thousandth the size of a strand of human hair and is invisible to the naked eye.

The DNA switch has been developed by British Molecular Biotechnology expert Dr Keith Firman at the University of Portsmouth working in collaboration with other European researchers.

Firman and his international team have been awarded a €2 million (AU$3.3 m) European Commission grant under its New and Emerging Science and Technology (NEST) initiative to further develop this groundbreaking new technology.

"The nanoactuator is a single molecule output for a generic sensor and the idea is to exploit biosensing technology using this device - the driving force is currently toxicity testing," Firman said.

Other applications such as generic biosensing, single molecule detection of events (such as dioxin binding) that can be detected at the single molecule level through an electronic output direct from the biosystem (the nanoactuator), may only be four years away according to Firman.

The technology could also be used in molecular-scale mechanical devices for interfacing to computer-controlled artificial limbs.

"The possibilities are very exciting. The nanoactuator we have developed can be used as a communicator between the biological and silicon worlds," Firman said.

"I could see it providing an interface between muscle and external devices, but it has to be pointed out that such an application is still 20 or 30 years away."

Firman noted that the 20-30 years wait relates to interfacing such a device to a human and that the delay is mostly about ethical considerations relating to implant of nanodevices.

The molecular switch comprises a strand of DNA anchored in a miniscule channel of a microchip, a magnetic bead and a biological motor powered by the naturally occurring energy source found in living cells, adenosine triphosphate (ATP).

These elements working together create a dynamo effect which in turn generates electricity. The result is a device that emits electrical signals that can be sent to a computer. The switch, therefore, links the biological world with the silicon world of electronic signals.

The nanoactuator has been patented by the University of Portsmouth, and a patent application for the basic concepts of biosensing is pending. Agreement between the international partners is still being sorted.

"The European Commission funding for this project will last three years and at the end of that we hope we will have a prototype biosensor capable of single-molecule signalling," Firman said.

"Commercialisation involves incorporation of this prototype into a suitable sensing system and we are collaborating with a UK company to do this - the possibility exists of a useful handheld device in four years if all goes well!"