NANOMORPHOLOGY AND SERS ACTIVITY IN PLASMA PREPARED SILVER SURFACES

A plasma oxidation-reduction process has been found to be suitable for producing silver surfaces showing surface enhanced Raman (SERS) activ ity. SERS spectra of monodisperse polystyrene films have been obtained by using these surfaces in order to study the correlation between enh ancement and nanomorphology as probed by atomic force microscopy. It w as found that the enhancement is strongly correlated with a coalescenc e of the initially present silver grains (10-50 nm in size). This coal escence leads to the formation of 100-300 nm silver hills in which eac h silver grain is still clearly distinguishable. The increase in the e ffective surface area due to the particle coalescence has been correla ted to the SERS enhancement in straightforward fashion. (C) 1997 Elsev ier Science B.V.