Development of new flexible ink films and plastics for SERS

Surface-enhanced Raman Scattering (SERS) involves amplification of Raman scattering by interaction with surface plasmons. The enhancement occurs when the frequency of the laser excitation is resonant with the surface plasmons on a rough metal surface, which is usually silver. Although hand-held Raman/SERS instruments are now available, the necessary low cost substrates are not. Ideally, a substrate for SERS should be inexpensive, robust, stable, reproducible, active, easily-prepared and stored film. The development of such a film would open up considerably the area of SERS in analytical chemistry in general and, most importantly, allow its use in routine, in-the-field sampling. Earlier work carried out by Prof. Mills established that photocatalytically deposited Ag on a sol gel film of TiO2 creates a highly effective surface for SERS. However, such sol gel films are not physically robust, nor simple to scale up. In this project novel photocatalytically active plastic films will be used to create a range of new, inexpensive, scalable, flexible, SERS active films - based on printable inks and extruded plastic films.

This project will explore: (i) a new approach to producing SERs materials, (ii) inexpensive, reproducible, scalable, commercially-viable printable inks and extruded plastic SERS active films produced, (iii) deposition of a wide range of under-explored, SERS-active metals (such as Hg, Pb, and Cu), as well as well established (such as Au and Ag) studied and performance optimised and (iv) control of metal particle size and shape through variation of deposition conditions. Prof Mills who will be the PI on the project, has considerable experience in the study of photocatalysis and the creation of smart inks and films. Prof. Bell, who is the project co-I, is a world-leading expert in Raman spectroscopy, with extensive experience in the production and testing of new materials for SERS.