Techniques employed in vibrational spectroscopy monitor the vibrational modes of
functional groups within biomolecules and enable a correlation between chemical
information and histological structures. Interrogation of biological samples using
infrared (IR) techniques generates spectrum with wavenumber-absorbance intensities
specific to biomolecules within the sample. Methods are relatively non-destructive,
and so samples can subsequently be analyzed by more conventional approaches.
Analyses can be carried out ex vivo or in situ in living tissue, where a reference range
of a designated normal state can be derived, and anything lying outside this range is
potentially atypical. Computational approaches allow one to minimize within-category
confounding factors. The application of vibrational spectroscopy in contaminant
biomonitoring is a welcome development which has enabled the investigation of realtime
contaminant exposure effects in the tissues of sentinels. IR techniques such as
attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, was
able to detect changes in various tissue samples exposed to varying levels of
polycyclic aromatic hydrocarbons (PAHs). This technique discriminated between
spatial and temporal variations in the interrogated tissues. Multivariate analysis was
able to relate the alterations at various regions of the fingerprint, to PAH exposure and
was able to detect PAH exposure in tissues from sites with no documented knowledge
of contamination. ATR-FTIR detected PAH-induced changes in isolated nuclei of
cultured cell populations in G0/G1 and S- phases of the cell cycle. Findings from the
various projects affirm, that techniques involved in IR spectroscopy are highly
sensitive to minimal changes in cell molecules. The ability to generate rapid results in
real-time is valuable and the wide variety of sample types which can be interrogated
using IR techniques makes it a suitable technique for environment biomonitoring.