# Scanning Electron Microscopy Techniques in the Analysis of Gunshot Residues: A Literature Review
## 3 Results
### Applications of SEM  
Scanning electron microscopy is a versatile and powerful technique used in multiple scientific and industrial fields to analyze and characterize materials and structures at the microscopic level. SEM has applications in nanotechnology, biology, the electronics industry, and beyond. Its ability to provide high-resolution, detailed images of sample surfaces makes it indispensable for a wide range of research and industrial applications. In nanotechnology, SEM is essential for the analysis and characterization of nanomaterials and nanostructures. Its high resolution enables the observation of details at the nanometric level, providing critical information on the morphology, size, and distribution of nanoparticles [14]. Another major application of SEM is in materials science and metallurgy, where it is used to analyze material microstructures, identify defects, and study failure mechanisms. It is particularly useful for examining the surfaces of metals, alloys, and composites to evaluate their quality and performance [15]. In the electronics industry, SEM is used to examine the structure and quality of electronic components and integrated circuits. It allows for the identification of manufacturing defects, observation of material distribution, and analysis of the interfaces between different components [16]. In geological and natural materials sciences, SEM is used to analyze minerals, rocks, and other natural materials, providing insights into their structure, composition, and the geological processes that influenced their formation [17]. In nanoscience, SEM plays a crucial role in developing and characterizing nanostructures and nanoscopic devices. It enables the visualization of nanotubes, nanoparticles, and nanowires and is essential for the research and development of emerging technologies [18]. In biology and medicine, SEM is widely used to study the morphology of cells, tissues, and organs. It allows for the observation of the fine details of cellular structures and interactions between cells and pathogens, making it particularly useful for analyzing biological samples that require high resolution [19]. SEM offers a wide range of applications in medicine, from the detailed characterization of cell and tissue structures to the analysis of pathogens and biomaterials. Its ability to provide high-resolution, detailed images is critical for medical research and diagnostics. In cell morphology studies, SEM enables the acquisition of detailed images of cell surfaces, revealing structures such as microvilli, cilia, and other cellular extensions that are not visible with optical microscopy. This capability is fundamental for studying cellular alterations due to diseases or treatments [20]. In tissue and organ analysis, SEM is used to examine the structure and composition of tissues and organs at a microscopic level. This technique is particularly useful for identifying pathological changes, such as modifications in adipose  
Figure 1: Time bar from PubMed illustrating the trend of publications over time about “gunshot residues analysis”. This graph shows the number of scientific papers published on the selected topic between 2000 and 2025, highlighting the evolution of research interest in the field. tissue structure or cell membranes during diseases [21]. Another rapidly growing field is pathogen analysis, where SEM is used for observing and analyzing bacteria, viruses, and other pathogens. It enables the visualization of pathogen morphology with high resolution, contributing to the understanding of their characteristics and the development of therapeutic interventions [22]. SEM is also used to study biomaterials and medical implants, such as prosthetics and suture materials. The technique helps evaluate the quality and durability of materials, cell adhesion, and interactions between biomaterials and tissues [23]. In cancer research, SEM is used to examine cellular alterations associated with diseases such as cancer.