Martin Fleishmann, James McQuilian, and Patrick Hendra discovered surface enhanced Raman spectroscopy (SERS) here in Chemistry at Southampton in the 1970s when they found that the Raman signal from pyridine adsorbed on a roughened silver electrode was a million times more intense than predicted.
Martin Fleishmann, James McQuilian, and Patrick Hendra discovered surface enhanced Raman spectroscopy (SERS) here in Chemistry at Southampton in the 1970s when they found that the Raman signal from pyridine adsorbed on a roughened silver electrode was a million times more intense than predicted. Since this time there have been 1000s of papers published that either tried to explain the origins of the SERS enhancement or have used SERS active surfaces to study the adsorption of molecules on such surfaces. However, these traditionally prepared SERS surfaces are not very stable (their performance degrades with time and/or at certain potentials, when used as an electrode), they can not be easily reused, and their inherent roughness means that it is difficult to understand the specific adsorption site of the molecules under investigation. In the last 10 years we have been developing a SERS substrate that addresses all of these issues. Our sculpted substrate is prepared by the electrodeposition of the surface of interest through a self-assembled colloidal crystal template of latex spheres. The resulting surfaces are smooth, reproducible, can be cleaned, and have excellent shelf lives. Together with Prof. Bartlett (also in the Electrochemistry section) and Prof. Baumberg (now in Physics at Cambridge), we have explored how the parameters that define our substrates (sphere diameter, film thickness, and metal) influence the SERS enhancements obtained. We are now focusing on using our substrates to explore a variety of electrochemical problems such as electrocatalytic reactions and the structure of the electrode/electrolyte interface in non-aqueous electrolytes.
Figure: SEM image of one of our SERS substrates (left) and artist's impression of the structure (right).