Production of metal nanoparticles by laser ablation techniques and their application as bactericidal agent

Resumo

In recent years, very significant advances in the field of nanotechnology are being achieved thanks to the new properties that appear when the matter is manipulated on a nanometric and sub-nanometric scale. In the nanometric scale, the properties of the materials differ from those corresponding to the bulk material, which implies the appearance of new properties (electronic, optical, catalytic, magnetic, etc.) leading to different and novel applications. On the other hand, more and more infections caused by resistant microorganisms, fail to conventional treatments. In this sense, it is estimated that by 2050, 10 million people could die if this tendency continues, due to the resistance of the bacteria to be treated with antibiotics. In light of this situation, it is necessary to explore new alternatives and metallic nanoparticles could be a solution. There are several research techniques that pursue the production of metal nanoparticles. Although each technique has its own pros and cons. Regarding the use as a bactericidal agent in humans, it is important to keep in mind that most of these methods involve the use of precursors, solvents or chemical reactions that can cause contamination of the obtained nanoparticles. This could be harmful not only for bacteria but also for surrounding tissues. Laser ablation of solids in liquids (LASL) allows to control the size and shape by adjusting the processing parameters, but also allows to obtain pure nanoparticles without the need for any additional reagents. This thesis is part of the research line of "laser material processing" and its main objective is the production of metal nanoparticles using laser-assisted techniques, for its application bactericidal agent.