This study provides a clearer understanding of the capabilities and limitations of surface-enhanced Raman spectroscopy (SERS) in forensic hair analysis.
This study analyzing how the different physical properties of contaminants can influence the collected spectra provides a clearer understanding of the capabilities and limitations of surface-enhanced Raman spectroscopy (SERS) in forensic hair analysis. The authors used 11 household substances of varying viscosity and opacity to contaminate hair dyed with permanent black or semi-permanent blue dyes. The authors discovered that contaminant opacity generally does not affect the spectral quality but that high contaminant viscosity does and that acidic substances could destroy the colourant's spectral identity altogether. Trace evidence found at crime scenes is rarely in an unsullied condition. SERS is a modern analytical technique that can be used for the detection of artificial hair colourants (S. Higgins and D. Kurouski, Surface-Enhanced Raman Spectroscopy Enables Highly Accurate Identification of Different Brands, Types and Colors of Hair Dyes, Talanta, 2022, 251, 123762). However, contaminants pose a problem to collecting accurate spectra from the dyes. Cleaning the contaminated hair with a water rinse allowed the underlying colourant to be identified in 21 out of 22 cases. (Published Abstract Provided)