The current study examined the potential of surface-enhanced Raman spectroscopy (SERS) in identifying just over 30 different hair colorants.
Hair is present at nearly all crime scenes. Forensic analysis of hair can be used to establish a connection between a suspect and a crime scene or demonstrate the absence of such connection. Almost half of the people around the world color their hair; however, there is no robust and reliable forensic approach that can be used for a confirmatory analysis of artificial colorants present on hair. Results of the current study showed that individual colorants could be identified with on average 97-percent accuracy, and different brands can be identified with nearly 100-percent accuracy. The study also found that SERS offered nearly 100-percent accurate identification of the type of the colorant and on average 97.95 -percent accurate prediction of the hair color. These results demonstrate that SERS can facilitate the forensic analysis of hair to provide important information about the artificial colorants present on the analyzed specimens. (Publisher abstract provided)