SURFACE-ENHANCED RAMAN-SCATTERING FROM AN ETCHED POLYMER SUBSTRATE

An etched polymer was evaluated as a substrate suitable for routine SE R analysis and was found to perform similarly to crossed gratings and posted quartz wafers, Silver particles were layered onto sheets of etc hed poly-(ethylene terephthalate) by chemical reduction, sputtering, a nd vapor deposition. Enhancement factors ranged from 10(4) to > 10(5) for crystal violet on chemically reduced and sputtered surfaces, respe ctively. Ranges of linearity up to 3 orders of magnitude were attained with limits of detection of similar to 5 pg, The variability of respo nse was <20% RSD for both routinely and painstakingly prepared samples . To induce enhancements beyond those possible from the dry substrate, a thin film of water was held on the analyte-treated substrate surfac e in a liquid state. Typical spectra of nine analytes with amino, carb oxylate, and/or nitro groups were collected from the most active subst rate.