Ring Vibrations to Sense Anionic Ibuprofen in Aqueous Solution as Revealed by Resonance Raman

We unravel the potentialities of resonance Raman spectroscopy to detect ibuprofen in diluted aqueous solutions. In particular, we exploit a fully polarizable quantum mechanics/molecular mechanics (QM/MM) methodology based on fluctuating charges coupled to molecular dynamics (MD) in order to take into account the dynamical aspects of the solvation phenomenon. Our findings, which are discussed in light of a natural bond orbital (NBO) analysis, reveal that a selective enhancement of the Raman signal due to the normal mode associated with the C-C stretching in the ring, nu(C=C), can be achieved by properly tuning the incident wavelength, thus facilitating the recognition of ibuprofen in water samples.

Automated summary

We explore the potential of resonance Raman spectroscopy for detecting ibuprofen in diluted aqueous solutions. By utilizing a fully polarizable quantum mechanics/molecular mechanics (QM/MM) approach coupled with molecular dynamics (MD) to account for the dynamic aspects of solvation, we demonstrate that selectively enhancing the Raman signal associated with the C-C stretching mode in the ring can facilitate the recognition of ibuprofen in water samples.