Multidimensional Raman spectroscopic signature of sweat and its potential application to forensic body fluid identification

This proof-of-concept study demonstrated the potential of Raman microspectroscopy for nondestructive identification of traces of sweat for forensic purposes. Advanced statistical analysis of Raman spectra revealed that dry sweat was intrinsically heterogeneous, and its biochemical composition varies significantly with the donor. As a result, no single Raman spectrum could adequately represent sweat traces. Instead, a multidimensional spectroscopic signature of sweat was built that allowed for the presentation of any single experimental spectrum as a linear combination of two fluorescent backgrounds and three Raman spectral components dominated by the contribution from lactate, lactic acid, urea and single amino acids.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Raman microspectroscopy was used for nondestructive identification of sweat traces for forensic purposes. ► Calculated multidimensional spectroscopic signature of sweat allowed eliminating the effect of heterogeneity of sweat. ► Any sweat sample can be represented as the combination of two fluorescent backgrounds and three Raman spectral components. ► Spectroscopic signature of sweat was fitted to all of the dry sweat samples with high goodness-of-fit statistical results.