Deposition of silver onto British 2p coins has been demonstrated as an
efficient and cost effective approach to producing substrates capable of
promoting surface enhanced Raman scattering (SERS). Silver application to the
copper coins is undemanding taking just 20 s, and results in the formation of
multiple hierarchial dendritic structures. To demonstrate that the silver
deposition sites were capable of SERS the highly fluorescent Rhodamine 6G
(R6G) probe was used. Analyses indicated that Raman enhancement only occurs at
the silver deposition sites and not from the roughened copper surface. The
robustness of the substrate in the identification and discrimination of
illegal and legal drugs of abuse was then explored. Application of the drugs
to the substrates was carried out using spotting and soaking methodologies.
Whilst little or no SERS spectra of the drugs were generated upon spotting,
soaking of the substrate in a methanolic solution of the drugs yielded a vast
amount of spectral information. Excellent reproducibility of the SERS method
and classification of three of the drugs, 4-methylmethcathinone (mephedrone),
5,6-methylenedioxy-2-aminoindane (MDAI) and
3,4-methylenedioxy-N-methylamphetamine (MDMA) were demonstrated using
principal components analysis and partial least squares