Raman spectroscopy may help catch criminals

Criminals with a penchant for dyeing their hair could soon pay for their vanity!
Scientists using surface-enhanced Raman spectroscopy (SERS) have found a way to analyse hair samples at crime scenes to rapidly determine whether it was coloured and what brand of dye was used.
Richard P Van Duyne and Dmitry Kurouski from the Northwestern University in US note that analysing hairs for forensic investigations can be a labour-intensive and flawed process.
Testing samples for DNA requires an intact bulb or root, which isn't always present. Plus, the procedure is time-consuming, which can cause a large backlog of cases.
So investigators will often opt to use the more traditional method of visually comparing hair from a crime scene with samples from suspects using a microscope.

However, this technique does not necessarily provide conclusive results.

Van Duyne and Kurouski wanted to find a more practical and accurate way to analyse hair.
The researchers turned to SERS with a portable Raman spectrometer. SERS can detect minute amounts of illicit drugs, explosives, gunshot residue and body fluids.
With this method, the team could rapidly confirm whether hair samples, even microscopic ones, were dyed and what brand of colourant was used.
This highly sensitive technique could help forensic investigators analyse hair quickly in the field, the researchers said.
The research appears in the ACS journal Analytical Chemistry.