Lipid membrane ink gives nanometre resolution

Lipid membranes have been used as a biological ‘ink’ to draw in the nanometre region in a new technique developed by Leeds researchers. Resolution as low as six nanometres was possible with the new technique – much smaller than previously thought possible. “This is smaller than the active elements of the most advanced silicon chips and promises the ability to position functional biological molecules – such as those involved in taste, smell and other sensory roles – with high precision, to create novel hybrid bio-electronic devices,” said Professor Steve Evans from the University of Leeds. Researchers used Atomic Force Microscopy to controllably write and position lipid membrane fragments with high precision. “The method is much like the inking of a pen,” said PhD student George Heath. “However, instead of writing with fluid ink, we allow the lipid molecules – the ink – to dry on the tip first. This allows us to the write underwater, which is the natural environment for lipid membranes.” Previously, researchers were writing with lipids in air, which allowed them to achieve a resolution of microns – a thousand times larger than achieved here, said Heath. The research, published in Nano Letters, could help scientists understand the structure of proteins found in lipid membranes. These membrane proteins act to control what can enter our cells, remove unwanted materials and a variety of other important functions. “Currently, scientists only know the structure of a small handful of membrane proteins,” said Evans. “Our research paves the way to understand the structure of the thousands of different types of membrane proteins to allow the development of many new drugs and to aid our understanding of a range of diseases.” The work could find applications in renewable energy production and Evans is working with the University of Sheffield researchers to construct a fully working mimic of the way plants capture sunlight. They hope to be able to arbitrarily swap out the biological units and replace them with synthetic components to create a new generation of solar cells. Diffusion in low-dimensional lipid membranes