Characterization of polycyclic aromatic hydrocarbons using Raman and surface‐enhanced 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.

Au nanoparticles grafted on Fe3O4 as effective SERS substrates for label-free detection of the 16 EPA priority polycyclic aromatic hydrocarbons

“…6(a)). In this study, the area of the Raman laser spot was 0.0143 mm 2 [27], and the surface area for a single Fe 3 O 4 hemisphere is estimated to be~0.0006 mm 2 Fig. 6(a)).…”

“…The intense Raman peaks in the range 1200e1600 cm À1 were mainly recognized as the CeH bending modes. Peaks appearing at 300-1000 cm À1 with lower intensities are mainly attributed to the CeC bending modes coupling with the CeH bending modes [27]. It should be noted that the vibrational mode assignments only convey the most dominant oscillations, whereas in most cases, the predicted peaks are a result of the combined vibrations of multiple atoms and bonds within the molecule.…”

“…The lack of change in SERS peaks from the normal Raman spectra implies that the SERS enhancement may be primarily due to the electromagnetic mechanism [28]. Compared with the CeC bending modes, the CeH bending modes have a higher polarizability [27]. Consequently, the PAHs with a larger number of CeH groups, such as InP, BaP, and BgP, tend to have a higher SERS activity compared with PAHs with fewer CeH groups (i.e.…”

Recent advances in linear and non‐linear Raman spectroscopy. Part X

“…They identified characteristic Raman and SERS peaks for five PAH compounds and the limits of detection were established. Such information could be useful for developing SERS assays for simple and rapid PAH identification . Firkala and co‐workers have used SERS to study the behavior of substituted propenoic acids used in heterogeneous catalytic asymmetric hydrogenation.…”

Structural changes in perylene from UV Raman spectroscopy up to 1 GPa

“…Advantages of UV resonant Raman spectroscopy (UVRRS) were first demonstrated by Asher and Johnson in their study of PAHs. Characterization of PAH by Raman spectroscopy is a challenge with classical methods in the visible range and further more at high pressure. Recent X‐ray diffraction studies on PAHs, pyrene, and phenanthrene have shown that phase transitions occur at pressures under 2GPa.…”