Characterization of polycyclic aromatic hydrocarbons using raman and surfaceenhanced raman spectroscopy

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous atmospheric pollutants and food contaminants, which exhibit potent carcinogenicity, mutagenicity, and teratogenicity. Vibrational spectroscopy techniques, especially Raman spectroscopy and surfaceenhanced Raman spectroscopy (SERS), can be potentially used as an alternative technique to liquid and gas chromatography in PAH analysis. However, there is limited information on the intrinsic Raman and SERS fingerprints of PAHs. In this study, we have acquired the Raman and SERS spectra of seven PAH compounds and compared their experimental spectra with theoretical Raman spectra calculated by density function theory (DFT). The vibrational modes corresponding to the Raman peaks have also been assigned using DFT. Characteristic Raman and SERS peaks have been identified for five PAH compounds, and the limits of detection were estimated. Such information could be useful for developing SERS assays for simple and rapid PAH identification.