Síntese verde de nanopartículas metálicas mediada por extratos de Paullinia cupana (guaraná)

Abstract

Research in the area of ​​nanotechnology involving the preparation of metal nanoparticles by alternative methods has been spread by the Green Chemistry approach, and in view of the many problems that pervade conventional methods, new less environmentally friendly mediations allow exploring resource-using procedures. such as the use of plant extracts for the synthesis of metallic nanoparticles. The Amazon region has vast biodiversity in its flora and thus, guarana (Paullinia cupana) has substances that indicate potential for the synthesis of silver nanoparticles. The present work sought to investigate parameters with the aid of UV-Vis absorption electron spectroscopy to understand the formation of nanoparticles using different concentrations of guarana extract, monitoring the synthesis at different temperatures, and to verify through antibacterial tests the biocidal action of the formed nanoparticles. Among the methodologies studied, the condition with the highest concentration of guarana extract showed higher production of silver nanoparticles compared to the other conditions when at room temperature, evidenced by the higher absorbance regarding surface plasmon resonance of nanoparticulate silver. Also noteworthy is the ability to stabilize and increase the rate of formation of nanoparticles as a function of temperature increase. The metal nanoparticles were submitted to antibacterial tests, showing inhibitory activity against Staphylococcus aureus.