40 years ago, a technique now used for detecting tiny quantities of molecules, in situations from crime scene forensic analysis, to drug detection, to establishing the origins of works of art, was discovered.

But despite there being a dozen CSI shows that use this on American television, you probably never heard of it. 

In the early 1970s, researchers discovered that by roughening the metal surface upon which the molecules they were examining had been placed, they could increase the signal by which they could detect these molecules - by a million times. It became arguably the most sensitive method of analysis on surfaces that anyone has ever come up with.

The technique, called Surface Enhanced Raman Spectroscopy (SERS) now has countless uses across industries and around the world. Co-discoverer Professor Patrick Hendra of the University of Southampton, says, "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."

Earlier this week, the discovery of SERS was awarded a National Chemical Landmark blue plaque by the Royal Society of Chemistry. 

Now it is being taken to the next level again: stem cell therapy. 

Dr. Sumeet Mahajan, Senior Lecturer in Life Science Interface at the University of Southampton, says, “Up to now, scientists have used intrusive fluorescent ‘markers’ to track each cell, but this can alter or damage the cells and render them useless for therapeutic use. By using SERS, we can use very tiny particles of gold, less than 1000th of the width of a human hair, as ‘nanoprobes’ to enter cells.. Through this, we can enhance the observation of the natural vibrations of molecules within the cell and make this otherwise almost invisible motion, easily detectable. This makes us able to detect if drugs are reaching cells correctly, and to detect abnormalities within cells on a molecular level.”