Rapid Recognition of Isomers of Monochlorobiphenyls at Trace Levels by Surface-Enhanced Raman Scattering Using Ag Nanorods as a Substrate

Isomers and homologues of organic pollutants are hard to distinguish—especially in trace amounts—due to the similarities in their physical and chemical properties. We report here that by identifying the Raman characteristics of isomers of monochlorobiphenyls, these compounds can be recognized, even at trace levels, by using the surface-enhance Raman scattering method with silver nanorods as a substrate. When dissolved in acetone, 2-, 3-, and 4-chlorobiphenyls were detected at a concentration of 10⁻⁸ mol/L, at which their characteristic Raman peaks were visible. This study may provide a fast, simple, and sensitive method for the detection and recognition of organic pollutants such as polychlorinated biphenyls.