Uso de aluminato de estrôncio dopado com európio e disprósio como marcador luminescente para detecção de resíduos de disparo de arma de fogo

Abstract

Forensic ballistics is a fundamental area of forensic science, dedicated to the analysis of evidence related to the use of firearms in criminal activities. Among the aspects investigated, the detection and characterization of gunshot residues stand out, as they can provide valuable information about the firearm used, the distance of the shot, and even the possible identity of the shooter. Traditional detection methods, such as spectroscopy and scanning electron microscopy (SEM), are widely used, but they present challenges related to sensitivity, cost, and accessibility of the analysis. In this context, the development of new approaches for marking and identifying these residues has become an area of growing interest in the scientific community. A promising solution involves the use of luminescent materials that can be visualized under specific lighting, facilitating field detection without the need for sophisticated equipment. Among these materials, lanthanide-doped aluminates have stood out due to their photoluminescent properties, thermal stability, and resistance to adverse environmental conditions. Thus, this study aimed to investigate the feasibility of using europium- and dysprosium-doped strontium aluminate as a luminescent marker for gunshot residues. To this end, the compound was initially characterized by Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS), laser diffraction, X-ray diffraction (XRD), and Thermogravimetric Analysis (TGA). Afterward, three concentrations of the marker (5%, 10%, and 15%) were tested to assess its effectiveness in detecting the residues. Based on the results, the marker showed an average particle size of 64.43 ?m, a monocyclic structure, and high stability at high temperatures. SEM-EDS analysis demonstrated the presence of the marker on the surfaces of interest, while UV illumination allowed clear visualization of the residue after the shots. The results indicate that the 15% concentration presents the best performance in terms of residue adhesion and persistence. Therefore, the findings of this study suggest that the tested compound may be a promising tool for forensic investigations, allowing rapid and accurate detection of gunshot residues. In parallel with this project, a review article was developed focusing on the main techniques for identifying gunshot residues. [resumo fornecido pelo autor]