Estudo de método verde para produção de nanopartículas metálicas utilizando aminoácidos e luz

• Ano de defesa: 2014
• Autor(a) principal: Matos, Ricardo Almeida de [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo
• Palavras-chave em Português: Nanotechnology; Metallic nanoparticles; Photoreduction; Green chemistry; Amino acids; Nanotecnologia; Nanopartículas metálicas; Fotorredução; Química verde; Aminoácidos
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=1321119; https://repositorio.unifesp.br/handle/11600/47349

Metal nanoparticles (10-9 m) exhibit properties such as high surface area, the effect of quantum confinement and plasmon resonance (SPR). The combination of these features gives the metal nanoparticles different potential applications. Currently, the synthesis of these nanoparticles is mostly carried out by chemical reduction, which is effective but uses a number of toxic substances, which makes the process potentially harmful to the environment. Thus, included in the current search for environmentally friendly synthetic methods, this study aimed to produce nanoparticles of silver and gold using only milli-Q® water, AgNO3/HAuCl4, white light and amino acids, characterized as "green chemistry". In total 21 different amino acids were studied by evaluating the shape and size of the nanoparticles obtained. This study also enabled a greater understanding of the synthesis of metal nanoparticles with natural substrates, methodology widely explored in the current scientific literature. Experimentally it has been observed that the synthesis of silver nanoparticles (AgNPS) is possible with the amino acid cystine, histidine, methionine, tyrosine and tryptophan, whereas the synthesis of gold nanoparticles (AuNPs) was possible with almost all amino acids, being the best with aspartic acid, arginine, threonine, tryptophan and valine. The size of the nanoparticles obtained ranged from 5 to 100 nm, with spherical shape. Changes in pH were required to improve the stability of colloidal suspensions. The characterization techniques used were UV-Vis spectroscopy, fluorescence, zeta potential, transmission electron microscopy and energy-dispersive X-ray spectroscopy (EDX). Ways to recover/reuse formed nanoparticles were also evaluated.