Imaging the world

Southampton scientists changed the way we see the world when a research breakthrough led to major advances in a molecular imaging technique.

Surface Enhanced Raman Spectroscopy (SERS) provides information about the structure and behaviour of molecules and can identify substances using very small samples. It is now used worldwide in a multitude of ways - from helping medical scientists in the fight against disease to the identification of pigments used in old masters.

"SERS is arguably the most sensitive method of analysis on surfaces that anyone has ever come up with," says Professor Patrick Hendra, who discovered the technique in the 1970s with colleagues Martin Fleishmann and James McQuillan. "However, at the time we had no idea how important it would become beyond the academic world, or the vast range of applications that would be developed."

Raman spectroscopy - which can be used to identify molecules by analysing the way they vibrate when they interact with light - was first developed in the late 1920s. However, the Raman effect is very weak, and this limited its use. A breakthrough came when Patrick and his colleagues discovered that, by using the technique on the surface of certain specially prepared metals, the results could be hugely enhanced. This has enabled the development of SERS for countless uses in the laboratory and beyond.

SERS can analyse substances using very small samples and identify chemicals at very low concentrations, making it an extremely useful tool in a wide range of fields. "At Southampton we are currently using SERS to understand more about DNA fingerprinting and the genetic mutations that lead to conditions such as cystic fibrosis," explains Professor Phil Bartlett of Southampton's Electrochemistry Research Group. "Also, one our students is developing SERS applications for crime scene investigations."

Elsewhere, SERS has been developed for the identification of diseases such as cancer and Alzheimer's in biological samples and the detection of anthrax and environmental pollutants, to name just a few examples. It has also been used in the field of art conservation, helping restorers to identify the substances used in pigments.

"This is a technique that has changed the world," says Phil. "From the initial discovery at Southampton, SERS has developed into something that is used around the world and researchers are continuing to take it forward today."