Combining fingerprinting capability with trace analytical detection: surface-enhanced raman spectrometry

The demand to measure unique spectral information on trace analytes in complex samples continues to increase. This paper discusses surface-enhanced Raman spectrometric (SERS) methods which are currently being explored for molecular recognition at trace concentration levels. SERS is amenable to the analysis of solids, liquids and gases in a variety of experimental configurations for both qualitative and quantitative tasks. Batch and flow systems are also easily implemented in colloid SERS experiments. Typical instrumental systems for each of these analytical approaches are described and compared. The shape of the calibration graphs and the factors limiting the linear range of response are discussed. Other figures of merit, including limits of detection, precision and selectivity of measurement, are given. Applications to compounds of technical, environmental, biomedical and pharmaceutical interest are presented.