Surface-enhanced Raman spectroscopy for the analysis of smokeless gunpowders and macroscopic gunshot residues
Gunshot residues (GSR) result from the discharge of a firearm being a potential piece of evidence in criminal investigations. The macroscopic GSR particles are basically formed by burned and non-burned gunpowder. Motivated by the demand of trace analysis of these samples, in this paper, the use of surface-enhanced Raman scattering (SERS) was evaluated for the analysis of gunpowders and macroscopic GSR particles. Twenty-one different smokeless gunpowders were extracted with ethanol. SERS spectra were obtained from the diluted extracts using gold nanoaggregates and an excitation wavelength of 633 nm. They show mainly bands that could be assigned to the stabilizers diphenylamine and ethylcentralite present in the gunpowders. Then, macroscopic GSR particles obtained after firing two different ammunition cartridges on clothing were also measured using the same procedure. SERS allowed the detection of the particles collected with an aluminum stub from cloth targets without interferences from the adhesive carbon. The results demonstrate the great potential of SERS for the analysis of macroscopic GSR particles. Furthermore, they indicate that the grain-to-grain inhomogeneity of the gunpowders needs to be considered.
KeywordsDiphenylamine Forensic Gunpowder Gunshot residue SERS
V.M. and J.K. would like to acknowledge the support by ERC Starting Grant 259432. M. López-López and C. García-Ruiz thank the European Commission for the Project HOME/2011/ISEC/AG/4000002480 accomplished with the financial support of the Prevention of and Fight against Crime Programme European Commission—Directorate—General Home Affairs. This project has been funded with the support from the European Commission. This publication reflects the views of the author, and the European Commission cannot be held responsible for any use which may be made of the information contained therein. M. López-López thanks the Spanish Ministry of Education, Culture and Sports for the José Castillejo mobility grant. V.M. acknowledges the support by the project DFG GSC 1013 (SALSA).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This chapter does not contain any studies with human participants or animals performed by any of the authors.
- 28.Tkachenko A, Xie H, Franzen S, Feldheim DL. Assembly and characterization of biomolecule-gold nanoparticle conjugates and their use in intracellular imaging. Methods Mol Biol. 2005;303:85–99.Google Scholar