05 November 2010
Scientists from Switzerland have created a system that mimics the way the human nose recognises scents.
Stefan Matile and colleagues from the University of Geneva made an artificial membrane that can distinguish between a range of odour molecules. Their 'nose' uses differential sensing, a form of molecular recognition, to recognise subtle structural differences between the molecules. 'Our nose works by differential sensing in the membrane and differential sensing has been done almost everywhere except in the membrane,' says Matile.
The human nose can distinguish over 10,000 different smells using 350 receptors. Smell molecules, known as an odorants, interact with the receptors to create an overall 'fingerprint' that is recognised by the brain. Matile's system works by moving odorants across a lipid bilayer, an artificial cell membrane, using electrostatic interactions. Once across the membrane, this creates a fluorescent response, which is then measured to build up an electronic fingerprint of the smell. The team say they can distinguish a range of commercial perfumes using their nose.
The artificial nose builds up a fingerprint of odour molecules
'This highlights just how closely related this system is to the human system,' says Jon Steed, an expert in supramolecular sensing at the University of Durham, Durham, UK, who adds: 'You can adapt the chemistry to sense whatever you want.'
'The applications are broad and very promising,' says Matile. Steed adds that detection of low levels of molecules is important in many areas, for example in the detection of explosives or pollutants. Matile is now studying different forms of membrane transport in the system and how this affects its sensing capability.