UV-SERS measurements offer a great potential for environmental
or food (detection of food contaminats) analytics. Here, the UV-SERS
enhancement potential of various kinds of metal colloids, such as
Pd, Pt, Au, Ag, Au–Ag core–shell, and Ag–Au core–shell
with different shapes and sizes, were studied using melamine as a
test molecule. The influence of different activation (KF, KCl, KBr,
K2SO4) agents onto the SERS activity of the
nanomaterials was investigated, showing that the combination of a
particular nanoparticle with a special activation agent is extremely
crucial for the observed SERS enhancement. In particular, the size
dependence of spherical nanoparticles of one particular metal on the
activator has been exploited. By doing so, it could be shown that
the SERS enhancement increases or decreases for increasing or decreasing
size of a nanoparticle, respectively. Overall, the presented results
demonstrate the necessity to adjust the nanoparticle size and the
activation agent for different experiments in order to achieve the
best possible UV-SERS results.