Tiny "James Bonds" could enable doctors to perform "diagnostics in a cell" to identify a wide range of diseases in the future.
A simple version of these "molecular machines" is already in use in ambulances across the world, the BA festival was told yesterday.
The technique involves persuading synthetic molecules to perform Boolean logic operations, explained Prof AP de Silva from Queen's University Belfast. These can then "light up" if a particular substance in a blood sample exceeds a pre-determined limit, he said.
The existing device detects the electrolyte sodium in blood, said Prof de Silva. Electrolytes levels can be disrupted by conditions such as dehydration and kidney dysfunction. "It acts as a molecular machine where sodium serves as an input and fluorescence as an output. It glows like a Christmas tree when it sees sodium. In this case, simple input logic operations have a use for actually saving lives."
Importantly, these techniques use light as an energy source, which means that the diagnostics can be performed in locations where traditional laboratory equipment is not available, such as many parts of the Third World, he said.
At the moment, the diagnostic system uses only a single molecular machine to look for a single electrolyte, sodium. In the future, Prof de Silva believes small molecular "spots on a piece of plastic" could each represent a different disease. These simple diagnostic techniques could have important implications for health in less developed nation, he added.
"Any intelligent diagnostic system that has a human interface requires high levels of education and resources. In future, you may be able to take a drop of blood, stick it on a little machine, and a light will come on to indicate a particular disease. This would be a self-contained system that could quickly and easily screen for risk of particular conditions."
Ultimately, the molecules may even be able to enter the cells themselves to perform diagnostics, said Prof de Silva. "You could have one hundred molecules, little James Bonds which infiltrate a pile of cells. These cells could be sorted and you'd be able to say 'if that glows blue, this person is at risk of Alzheimer's' or 'this next guy is going to be a cardiac case'. These are places that semi-conductors just cannot go."
Dr Vikki Burns is a scientist from the University of Birmingham on placement at The Irish Times as a media fellow for the British Association for the Advancement of Science